Synthetic images with animations that have perceived depth.

Abstract

A method for manufacturing a synthetic image device includes providing (S10) an array of focusing elements. An image layer is arranged (S20) near the focal length of the focusing elements, whereby a synthetic image composed of a magnified portion of the image layer becomes perceptible to a viewer. The image layer includes an array of image units, each image unit associated with a corresponding focusing element. The step of arranging (S20) the image layer includes creating (S22) a corresponding image object within each corresponding image unit in the image units. These image objects make an animation perceptible, the animation comprising a series of synthetic images that are continuously perceptible as the viewing direction changes. These image objects make each of the synthetic images in the series perceptible at a corresponding perceptible depth, the corresponding perceptible depth varying between the synthetic images in the series.

Description

Technical Field

[0001] This invention relates generally to optical devices and their manufacturing processes, and more specifically to synthetic image devices and their manufacturing methods. Background Technology

[0002] Composite image devices are now frequently used to create striking visual effects for a variety of purposes. Examples of use include, for example, secure documents, security tags, tamper warnings, or simply aesthetically pleasing images. Typically, composite image devices are intended to be provided as labels or as an integrated component of another device. Many different optical effects have been discovered and used, and these effects are often combined to give a specific desired visual appearance.

[0003] A typical composite imaging device presents a small array of focusing elements and image objects created in different planes of a thin foil. The focusing elements can be various types of lenses, apertures, or reflectors. An image layer contains the image objects. The image layer is provided relative to the array of focusing elements so that when the device is viewed from different angles, different portions of the image objects are magnified by the focusing elements and together form a unified image. Depending on the design of the image objects, the composite image can change in different ways when viewing conditions (e.g., viewing angle) change. A typical implementation of a composite imaging device is a thin polymer foil.

[0004] The actual perception of a synthesized image is accomplished by the user's eyes and brain. The human brain's ability to create an understandable whole from fragmented images can be used to create "surprising effects." These striking effects are often used for security and / or authentication purposes.

[0005] One commonly used and simple type of "surprising effect" is the provision of depth perception. Because synthetic imaging devices are typically thin and flat, the synthetic image appears to be positioned above or below the surface of the device, creating a "strange" experience. The synthetic image looks like it's floating above the surface, or appears to exist below it. This effect is supported by providing a synthetic image that changes according to the parallax properties of whether the image is above or below the surface. This effect becomes particularly striking if the image is a true 3D image, i.e., when the object being depicted itself extends in the depth direction.

[0006] Another frequently used surprising effect is the shift from one synthetic image to another when the synthetic image device is tilted (i.e., by changing the viewing direction). This abrupt change in the synthetic image does not follow the pattern experienced when viewing a real object, thus presenting a surprising effect. This is illustrated, for example, in published international patent application WO 94 / 27254A1, in which... Figure 2 A and Figure 2 B shows that different images are provided in different directions.

[0007] Even more striking effects might be the gradation of synthesized images. This is typically achieved by providing a series of "sudden" changes, but with relatively small differences between each different synthesized image. This produces a gradual animation using synthesized images. Different methods have been proposed.

[0008] In published U.S. Patent 8,739,711 B2, a micro-optical security device is presented that employs a planar arrangement of stitched icons and projects a composite magnified image. The composite magnified image constitutes an image that optionally changes into different images as the security device is tilted to provide different viewing angles. The image layer comprises slices from one or more icon designs, wherein each slice is spaced apart from, adjacent to, or slightly overlaps with adjacent slices.

[0009] Therefore, each slice represents a different image. By providing icon designs with continuously changing images, a series of progressively changing images can be provided when tilted. The "smoothness" of this gradual image change depends primarily on the number of continuously changing images, which in turn depends on the size of the icon design slices used. More slices with fewer changes within related images will increase the smoothness. Ultimately, the available geometric resolution of the provided icon limits this smoothness.

[0010] Furthermore, published international patent application WO 2018 / 101881 A1, for example, in conjunction with Figures 27A to 27D, Figures 28 and 29A to 29B, and pages 40-43, discloses a synthetic image apparatus with morphing or animation properties. In some embodiments, the image units of the synthetic image apparatus are divided into channels, which include image objects for creating corresponding synthetic images. By providing synthetic images that gradually change their appearance within these channels, gradual morphing or animation is achieved. Again, the size of the channels and the differences between adjacent synthetic images determine the smoothness. Due to physical limitations, the channels and the geometry within the channels cannot be correctly generated.

[0011] When using animation to verify the authenticity of security documents, the documents are examined from various viewing directions, and any animated or other optical behavior is compared to a reference behavior. The reference behavior defines how the animation or other optical behavior should behave to demonstrate the authenticity of the security document. If the reference behavior is too complex, it can be difficult to remember and compare. Therefore, a new type of animation is needed that is easy to understand and compare with expected animated behavior. Summary of the Invention

[0012] Therefore, the general objective is to provide a synthetic image device that provides animations that are easy to understand and compare with the intended animated behavior.

[0013] The above-mentioned objectives are achieved by the method and apparatus according to the independent claim. Preferred embodiments are defined in the dependent claims.

[0014] Generally, in a first aspect, a method for manufacturing a synthetic image device is provided. The method includes the steps of: providing a focusing element array and arranging an image layer near the focal length of the focusing elements in the focusing element array, whereby a synthetic image composed of a magnified portion of the image layer becomes perceptible to a viewer. The image layer includes an array of image units, wherein each image unit is associated with a corresponding focusing element in the focusing element array, and wherein the element distance of the image unit array is the same as the element distance of the focusing element array. The step of arranging the image layer includes creating a corresponding image object within each corresponding image unit in the image units. The image object makes an animation perceptible, the animation comprising a series of synthetic images that can be continuously perceived as the viewing direction changes from a first viewing direction to a second viewing direction. Further, the image object makes each of the synthetic images in the series perceptible at a corresponding (stereo) depth, which varies between the synthetic images in the series. The depth variation throughout the animation utilizes at least three different depths.

[0015] This method provides a way to create a synthetic image device that implements view-dependent animation that perceives stereo depth. View-dependent animation that perceives stereo depth produces a clear and defined effect, making it suitable for secure files.

[0016] In a second aspect, the image synthesis device includes a focusing element array and an image layer. The image layer is arranged near the focal length of the focusing elements in the focusing element array, thereby making the synthesized image, composed of a magnified portion of the image layer, perceptible to the viewer. The image layer includes an image unit array, wherein each image unit is associated with a corresponding focusing element in the focusing element array, and wherein the image unit array has the same element distance as the focusing element array. Each image unit includes an image object, and the image object makes an animation perceptible, the animation comprising a series of synthesized images that can be continuously perceived as the viewing direction changes from a first viewing direction to a second viewing direction. Moreover, the image object makes each of the synthesized images in the series perceptible at a corresponding (stereo) depth, which varies between the synthesized images in the series. The depth variation throughout the animation utilizes at least three different depths.

[0017] One advantage of the proposed technique is that it provides synthetic image animation with viewpoint-dependent depth, which is easily understood by the viewer and compared with corresponding reference behavior. Other advantages will be understood when reading the detailed implementation. Attached Figure Description

[0018] The invention and its further objects and advantages can be best understood by referring to the following description taken in conjunction with the accompanying drawings, in which:

[0019] Figures 1A to 1C This is a schematic diagram of a composite image device that utilizes different focusing elements.

[0020] Figure 2 It is a diagram showing the view from different angles.

[0021] Figures 3A to 3B It demonstrates the formation of a composite image from two different perspectives.

[0022] Figures 4A to 4C This demonstrates an idea of ​​forming an integrated synthetic image device.

[0023] Figure 5 Another example of an integrated composite image device is shown.

[0024] Figure 6 Examples of how 3D images can be created are shown.

[0025] Figures 7A to 7D This illustrates the creation of animated composite images.

[0026] Figure 8A A portion of an embodiment of a digital image model used to provide synthetic image animation is shown.

[0027] Figure 8B Showing Figure 8A The magnified portion, in which digital image units and their subdivisions are marked with boxes to indicate their extent.

[0028] Figure 9 This is a flowchart of the steps of an embodiment of a method for manufacturing a synthetic image device.

[0029] Figure 10A It schematically illustrates the overlap between repeating digital icon images and patterns of digital unit parts related to a viewpoint.

[0030] Figure 10B schematically shown Figure 10A How the digital icon image pattern is cropped / truncated / masked by the pattern of the digital image unit part to obtain the digital sub-image of each digital image unit part.

[0031] Figure 10C It schematically illustrates the overlap between repeating digital icon images and patterns of digital unit parts related to another perspective.

[0032] Figure 10D schematically shown Figure 10C How the digital icon image pattern is cropped / truncated / masked by the pattern of the digital image unit part to obtain the digital sub-image of each digital image unit part.

[0033] Figure 10E It schematically illustrates the overlap between the repeating digital icon image and the pattern of the digital unit portion, which are related to yet another perspective.

[0034] Figure 10F schematically shown Figure 10E How the digital icon image pattern is cropped / truncated / masked by the pattern of the digital image unit part to obtain the digital sub-image of each digital image unit part.

[0035] Figure 10G It schematically illustrates the overlap between the repeating digital icon image and the pattern of the digital unit portion, which are related to yet another perspective.

[0036] Figure 10H schematically shown Figure 10G How the digital icon image pattern is cropped / truncated / masked by the pattern of the digital image unit part to obtain the digital sub-image of each digital image unit part.

[0037] Figure 10I yes Figure 10A , Figure 10C , Figure 10E and Figure 10G The merger.

[0038] Figure 10J yes Figure 10B , Figure 10D , Figure 10F and Figure 10H The merger.

[0039] Figure 10K The diagram schematically illustrates the pattern of a digital image unit being far from the registration point of the pattern.

[0040] Figure 10L Showing Figure 10K Merging with points intended for spline interpolation.

[0041] Figure 10M Showing Figure 10K Merging with B-spline approximation performed on two units.

[0042] Figure 11yes Figure 9 The flowchart shows a portion of the steps in an embodiment of step S22.

[0043] Figure 12 Another embodiment of a digital image model used for animation synthesis is illustrated schematically. Specifically, the figure shows different spacing / cycles between repeating digital icon images for each viewpoint, and the digital icon images are similar for each viewing direction.

[0044] Figures 13A-1 to 13A-3 A screenshot of an image layer showing one example of a depth animation of the number "5".

[0045] Figures 13B-1 to 13B-3 A screenshot of an image layer showing another example of a depth animation of the number "5".

[0046] Figures 14A to 14D Different embodiments of the image unit are shown; and

[0047] Figures 15A to 15C Different embodiments of the digital image unit section are shown. Detailed Implementation

[0048] In all the accompanying drawings, the same reference numerals are used for similar or corresponding elements.

[0049] To better understand the proposed technique, it may be helpful to begin with a brief overview of the synthetic image apparatus. This initial overview is provided to understand the basic properties of synthetic images. However, the simplest type of synthetic image mentioned herein (e.g., a pure ripple image) is not suitable for the purposes of this invention.

[0050] Figure 1A An example of a composite image apparatus 1 is schematically shown. The composite image apparatus 1 includes a focusing element array 20 of a focusing element 22. In this example, the focusing element is a lens 24. In typical cases where the composite image is intended to be substantially identical in different surface orientations, the lens 24 is usually a spherical lens. In applications where there are differences in image properties between different surface orientations, a biconvex lens can be used. Depending on the application, other types of lenses, such as polygonal lenses, zone plate lenses, etc., can also be advantageously used.

[0051] The image synthesis device 1 further includes an image layer 10, which includes an image object 12. The image object 12 defines the content of the image layer 10. The image object 12 can have any content, such as being at least partially empty and / or at least partially composed of items optically distinguishable from their surroundings. The image object 12 can include, for example, features 11, such as micro-features of a printed product and / or embossed microstructures, and portions 11B without any specific features. The image layer 10 is arranged near the focal length d of the focusing element 22 in the focusing element array 20. This means that a parallel light beam 6 incident on the focusing element 22 will be refracted 5 and focused at a small area (also referred to herein as image point 4) at the image layer 10. Similarly, light emitted from an image point 4 at the image layer 10 will produce a parallel light beam 6 as it passes through the focusing element 22. Therefore, when a viewer looks from a distance in the direction of the produced parallel light beam 6 (this is schematically shown by the eye of viewer 2), the image point 4 at the image object 12 will appear to fill the entire surface of the focusing element 22. The material 9 between the image layer 10 and the focusing element array 20 is at least partially transparent and is typically composed of a thin polymer foil.

[0052] The distance d need not be exactly equal to the focusing distance of the focusing element 22. First, there is always some degree of aberration, which, in any case, widens the area from which optical information in the parallel beam 6 is collected. This is more pronounced at shallower angles, and in order to have a more uniform general resolution level, it is advantageous to choose a distance near but not exactly equal to the focal length. Furthermore, since the surface of the focusing element has a certain two-dimensional extension, this surface can also be used to generate fine objects in the entire composite image. In this case, fine objects in small areas on image layer 10 can be advantageously magnified to cover the surface of the focusing element, meaning that in this case, the actually chosen distance d is also chosen to be near but not exactly equal to the focal length. Such a situation is well known in the field of composite images.

[0053] By arranging / designing the image objects 12 of the image layer 10 in a suitable manner, the partial images generated at the surface of each individual focusing element 22 will be collectively perceived by the viewer 2 as a composite image. These partial images correspond to the corresponding image points 4 that are part of the corresponding image objects 12 at the image layer 10. When the composite image device 1 is viewed in different directions, different images can be displayed to the viewer, which opens the way for creating different kinds of optical effects, as will be described further below.

[0054] Figure 1BAnother example of the image synthesis device 1 is illustrated schematically. In this embodiment, the focusing element 22 is composed of a concave mirror 26. The image layer 10 is located on the front surface relative to the viewer 2, and the focusing element array 20 is located behind the image layer 10. Light 5 propagating from the image object to the viewer 2 passes twice through the material 9 of the image synthesis device.

[0055] Figure 1C Another example of the image synthesis device 1 is illustrated schematically. In this embodiment, the focusing element is a pinhole 28, which restricts the light from the image layer 10 and through to the viewer 2. In this embodiment, the synthesized image is established by a narrow beam of light passing through the pinhole 28 and typically only provides "light" or "darkness". Since the pinhole 28 does not have any magnification effect, most of the viewing surface does not contribute to the synthesized image.

[0056] Figure 2 The selection of different portions or image points 4 of image layer 10 is schematically shown. Image layer 10 includes features 11 of image object 12. When the composite image device 1 is viewed in a viewing direction 3 perpendicular to the main surface of the composite image device 1, as shown in the left portion of the figure, the image point 4 magnified by the focusing element 22 is located at the center line of the focusing element 22, which is shown as a dashed line in the figure. A magnified version of any content of the image object 12 at this location (e.g., feature 11 or a portion 11B without any specific features) is presented on the surface of the composite image device 1. However, as in Figure 2 In the case where feature 11 is absent, and only a magnified image of part 11B without any specific features will exist on the surface of the image synthesis device 1.

[0057] When the image synthesis device 1 is viewed from another angle (e.g., as shown in the right part of the figure), the image point 4 focused on by the focusing element 22 is offset laterally. In the illustrated case, the image point 4 overlaps with at least a portion of feature 11, and a magnified version can be seen at the surface of the image synthesis device 1. In this way, the image presented at the surface of the image synthesis device 1 can be varied for different viewing angles, which can be used to achieve different kinds of optical effects in the synthesized image. Therefore, there is a correlation between the position of the image point 4 and the viewing direction 3 in which the image point 4 contributes to the synthesized image.

[0058] One type of composite image is the so-called moiré magnifier. The moiré magnification effect has been known for many years and is based on the cooperation of two slightly mismatched arrays. These basic findings are disclosed, for example, in the following literature: “The moirémagnifier”, MC Hutley et al., Pure Appl. Opt. 3 (1994), pp. 133-142. Figure 3A An example of a portion of image layer 10 is schematically shown at the top. Image layer 10 includes a repeating pattern of icon image 15. In this example, icon image 15 is chosen as the letter "K". Focusing elements 22 associated with the shown portion of image layer 10 are indicated by dashed circles to indicate their relative lateral position. Both the repeating pattern of icon image 15 and the array of focusing elements 20 exhibit hexagonal symmetry. However, the distance between two adjacent icon images 15 is slightly shorter than the distance between two adjacent focusing elements 22 in the same direction.

[0059] When viewed in the associated viewing direction, image point 4 is also marked, corresponding to the focal area of ​​each focusing element 22. In the case shown, image point 4 corresponds to the direction of direct frontal viewing. The portion of image object 12 present within each image point 4 is thus presented in a magnified version on the surface of the corresponding focusing element 22, which is represented here as projected image 25. Figure 3A The lower part shows the corresponding focusing element array 20, which includes the projected image 25 of the portion of the icon image 15 falling within image point 4. A dashed line from one of the image points 4 in the upper part to one of the focusing elements 22 in the lower part illustrates this relationship. The different projected images at the focusing elements 22 together form a composite image 100. In this case, the composite image 100 is part of a larger “K”. If these structures were small enough, the human eye would typically fill the blank area between the focusing elements 22, and the viewer would perceive the complete “K”. The reason for the “K” is a slight periodic mismatch between the repeating pattern of the icon image 15 and the focusing element array 20. In this example, using the mismatch between the repeating pattern of the icon image 15 and the array of focusing elements 22, the composite image 100 is referred to as the wavy image 105.

[0060] But when viewed from another direction... Figure 3B It schematically demonstrates the relationship with Figure 3A The same image synthesis device 1 is used. This corresponds to a slight leftward tilt of the image synthesis device 1. In this direction, the image point 4 corresponding to the focus area of ​​the focusing element 22 is thus slightly shifted to the left. This results in another set of image points 4 being projected onto the focusing element 22, as shown in the image synthesis device 1. Figure 3B What you see at the bottom. The result of the tilt is that the composite image 100 (i.e., the large "K") is shifted to the right.

[0061] Viewers interpret this motion as a result of the large "K" being positioned at some imaginary or apparent depth below the surface of the synthetic image device 1. In other words, a sense of depth is achieved. Both the magnification and the perceived depth depend on the relationship between the focusing element array 20 and the repeating pattern of the icon image 15. It has been shown in the prior art that the obtained magnification M is determined as:

[0062]

[0063] in,

[0064] Among them, P o It is the period of the repeating pattern of icon image 15, and P l This is the period of the focused element array 20. For P o <P l The magnification factor is positive for P. o >P l The magnification factor becomes negative, meaning that compared to image object 12, the composite image 100 becomes inverted.

[0065] When using spherical microlenses, the apparent image depth d of the ripple image i It can also be determined as:

[0066] d i =(dR) l (1-F)+R l (2)

[0067] Where d is the thickness of the image synthesis device, and R l It is the radius of curvature of the spherical microlens. It can be noted here that for P... o <P l Apparent depth is usually positive, while for P o >P l The apparent depth becomes negative, meaning that the ripple image 105 appears to float above the surface of the synthetic image device 1.

[0068] It can also be noted that for depths much larger than the microlens radius, the apparent image depth is roughly proportional to the magnification. This is true in virtually all practical cases, as microlens radii are typically on the order of 10-200 μm, while apparent depths are usually at least several millimeters. Generally, for lens arrays, the following relationship holds true:

[0069] d i =M(dR) l )+R l (3)

[0070] It should be noted that Figure 3A and Figure 3B The period difference shown is relatively large, resulting in a relatively low magnification and a relatively small apparent depth. This is for illustrative purposes. In typical ripple synthesis imaging equipment, the relative period difference is likely to be much smaller. Period differences of less than 1% and even less than 0.1% are not uncommon.

[0071] The concept of ripple images can be further extended. Figure 4A The image shown schematically illustrates an icon image 15 that is to be magnified using a wavy zoom. If this icon image 15 is compared with... Figure 4B If the focusing elements 22 repeat with almost identical periods, then icons 15 will overlap. A wavy image from such a structure is virtually impossible for the human brain to resolve because the portions of icon image 15 associated with adjacent focusing elements 22 will interfere.

[0072] Figure 4C A solution is presented in which image layer 10 is spatially divided into portions called image units 16. Each image unit 16 is uniquely associated with each focusing element 22, meaning that image unit 16 defines a non-overlapping portion of image layer 10. Image layer 10 thus comprises an array of image units 16, wherein each image unit 16 is associated with a corresponding focusing element in the array of focusing elements. The content of image layer 10 within the boundary of each image unit 16 is referred to herein as the “image object” 12 of that image unit 16.

[0073] Within each image unit 16, only the portion of the original repeating icon image 15 that is a copy of the repeating icon image 15 is retained as the so-called truncated icon image 17 of that image unit 16, and other interfering repeating icon images 15 are removed from the image object 12 of that image unit 16. Truncating the icon image 15 means that only the portion of the image icon 15 within the boundary of the image unit 16 is retained in the truncated icon image 17. Different truncations of the icon images 15 in different image units 16 result in changes rather than repetitions in the content of each nearby image unit 16 on the image layer 10. Composite images are also generated by using these clipped portions or small portions as truncated icon images 17. Composite images based on potentially different truncated icon images 17 within the image unit 16 associated with the focusing element 22 are referred to in this disclosure as a unified composite image.

[0074] Figure 5 The image shown is an example of a portion of image layer 10 of an integrated synthetic image device that produces the image of the number "5".

[0075] As long as the focal area (i.e., image point) of the associated focusing element remains within the image unit 16, a composite image resembling a wavy image is produced. However, when the change in viewing angle is sufficient to cause the focal area of ​​the associated focusing element to enter an adjacent image unit 16, the composite image will suddenly disappear and will instead appear in another position; a flip occurs in the composite image.

[0076] This can further advance the idea of ​​giving image units different image objects. Ripple-synthesized images can be given apparent depth, but are in principle limited to one depth. It is difficult to achieve a true three-dimensional appearance using ripple-synthesized images. However, when considering monolithic composite images, there is freedom to change icon images from one image unit to another. This freedom can also be used, for example, to provide a more realistic three-dimensionality to the resulting composite image.

[0077] exist Figure 6 The image layer 10 is shown with image units 16. Each image unit 16 has four distinct image points 4, which correspond to the focus areas of associated focusing elements when viewed from four different directions. The image object portion within the central image point 4 of each image unit corresponds to the viewing angle achieved when the composite image device is viewed vertically. Such image object portions can then be designed to produce a unified composite image 110B, as... Figure 6 The image shown is the lower middle portion of the top surface of the box. The image object portion of the uppermost image point 4 in each image unit 16 corresponds to the viewing angle achieved when the composite image device is tilted away from the viewer. Such image object portions can then be designed to produce a unified composite image 110A, as... Figure 6 The diagram shows the lower left portion of the top and front surfaces of the box. The leftmost image point 4 in each image unit 16 corresponds to the viewing angle achieved when the composite image device is tilted to the left relative to the viewer. Such image object portions can then be designed to produce a unified composite image 110C, as... Figure 6 The diagram shows the lower right portion of the top and side surfaces of the box. The image object portion of image point 4 in the lower right portion of each image unit corresponds to the viewing angle achieved when the composite image device is tilted to the right relative to the viewer. Such image object portions can then be designed to produce a unified composite image 110D, as... Figure 6 The diagram shows the bottom of the top, side, and rear surfaces of the box. These composite images 110A-D, together with additional composite images emitted from other image points of image unit 16, give a three-dimensional impression of the rotating box. Therefore, this variation in the composite image follows the expected parallax rule. In this case, the image properties thus achieved are a simulation of “real” optical properties, such as a real three-dimensional image with parallax variations.

[0078] In a similar manner, different kinds of optical phenomena can be achieved by modifying the image content (i.e., image objects) in each image unit separately. By adjusting the image objects of each part of the image unit in the corresponding viewing direction according to the desired image appearance, the synthesized image can have almost any appearance. Therefore, the image properties thus achieved can be designed to exhibit optical effects that do not exist in the "real" system, i.e., to have non-parallax features. One such image property that can vary for different viewing directions is the perceived depth of the synthesized image, and this is the type of variation for which this technique aims.

[0079] A simple effect is switching between different composite images in sectors at different angles. This is illustrated, for example, in published international patent application WO 94 / 27254A1. In this case, represented by a single image, the image layer is provided with more than one image unit associated with a single focusing element. Within each of these image units, an image object is provided, which produces a specific composite image. Since the area of ​​each image unit is finite, the angular direction in which the composite image is visible is also limited. Another typical example of such an arrangement can be found in Figure 47 of U.S. Patent 7,738,175B2. Here, multiple image units are provided, which are divided into sectors in the azimuth direction. This means that different composite images can be viewed in a limited azimuth viewing direction.

[0080] In this disclosure, slightly different terminology is used. A common image unit is associated with each focusing element. An image object is considered to be associated with features of this common image unit. This common image unit can then be divided into different image unit parts, with one image unit part for each composite image. The image object can extend over all such image unit parts, thereby including features from all composite images.

[0081] When viewed through a perspective associated with the boundary between two image unit parts, a flip will appear between the two composite images. If the differences between the individual composite images are small between consecutive adjacent image unit parts, a continuous change in the appearance of the image can be obtained. In other words, animation can be produced. Such gradients can be of various kinds, such as, but not limited to, shape, size, orientation, position, color, perceived depth, or combinations of several of these parameters.

[0082] This can be illustrated schematically in the diagram below. Figure 7A In the middle, it is shown that... Figure 3AA similar setup exists. However, in this case, the composite image device 1 is not a ripple device because the content of different image units will be different. Image layer 10 is divided into image units 16 in image unit array 7. Each image unit 16 is associated with a focusing element 22. To generate a "K" image, only a portion of the icon image within image point 4 is needed, thus forming a truncated icon image 17. Regardless of what exists outside these image points 4, when viewing the device from above, the large composite image 100 of the composite image in the form of "K" will be seen anyway. In this case, the portion of image point 4 of the image object produces a monolithic image 106 because it is based on the non-repeating truncation 17.

[0083] exist Figure 7B In this context, the perspective changes, and therefore, image point 4 shifts within image unit 16. In this case, the truncated icon image 17 in this perspective changes to the letter "Y". If the intermediate image point between the image points of the composite image given in these two figures is designed to form an intermediate design between the letter "K" and the letter "Y", then an animation of the letter K gradually changing into the letter Y can be achieved.

[0084] exist Figure 7C The image presents another perspective. At image point 4 associated with this perspective, there is a truncated "Y" icon image 17 that results in severe distortion. Similarly, here, only image object features contained within the image point contribute to the composite image 100 we see.

[0085] exist Figure 7D middle, Figures 7A to 7C The situation is compiled into an explanation. Within the marked image point 4, there exists sufficient image information to provide "K", "Y", and "distorted Y" in three different directions, as schematically shown at the bottom of the figure. The remaining portion of the image object 12 of image layer 10 outside the marked image point 4 can now be configured with features to generate other composite images. For example, if animation is requested, the area of ​​image object 12 of image layer 10 between the marked image points 4 can be filled with features that generate composite images somewhere between "K", "Y", and "distorted Y".

[0086] In this way, the entire image unit 16 can be filled, for example, by truncated icon images 17, which will produce different composite images 100 in different directions, thereby providing animation effects with unexpected three-dimensional parallax behavior.

[0087] To make such animations visually appealing and easy to understand, the variations between successive composite images should be minimal. This means that a large number of image objects must be provided within the corresponding image unit sections within each image unit to give the composite image. Since the total available space within an image unit is limited, the more steps there are between successive composite images, the smaller each individual image unit section must be.

[0088] When manufacturing composite imaging devices, the image layer is typically provided by printing or embossing onto a polymer film that also includes or is attached to the focusing element array. Once the image layer is formed on the polymer film, it is nearly impossible to fit any structures within that image layer. This means that any structures intended to be included in the image layer of the final product, whether basic image design, advanced image effects, or appearance enhancements, must be provided during printing / embossing. It also means that the definition of the structures to be printed / embossed must also include any appearance enhancement modifications or advanced image effects to the composite image or composite image animation of the original design. The definition of the image layer to be provided can be illustrated using a digital image model that includes an array of digital image units.

[0089] exist Figure 8A The image shows an example of a digital image model 101 with a simple animation of four steps. When the synthetic image device to be manufactured is tilted in the vertical direction (i.e., tilted about the horizontal axis), the synthetic image intended to be produced from the image object is transformed from an octagon and a square into a star-shaped circle. In a preferred embodiment, the number of steps would certainly be greater to achieve a smoother transition, but for the purpose of illustrating the principle, the number of steps is kept small. The digital image model 101 is also shown at a very high magnification. The typical size of the distance between adjacent focusing elements in the final product can be in the range of 15-150 micrometers, meaning that the associated size of the digital image unit 116 should be within the same range.

[0090] Digital image model 101 includes an array 107 of digital image units 116, of which only a few are labeled in the figure for visual purposes. Each digital image unit 116 is associated with a digital image object 117, which is marked with a dashed line in one of the image units. In this example, each digital image unit 116 is divided into four digital image unit portions 118, each portion corresponding to a corresponding viewpoint range in four different viewpoint ranges. In this embodiment, the digital image unit portions 118 have a horizontal band or stripe shape. Within each digital image unit portion 118, a digital sub-image 128 is provided. Since the intended composite image is animation, the digital sub-images 128 in each digital image unit portion 118 are different. In the uppermost digital image unit portion, the digital sub-image 128 is designed to produce a star-shaped composite image together with the digital sub-images 128 of the uppermost digital image unit portions of other digital image units. In the second uppermost digital image unit portion, the digital sub-image 128 is designed to produce a square composite image. In the next lower digital image unit section, the digital sub-image 128 is designed to produce an octagonal composite image. In the lowest digital image unit section, the digital sub-image 128 is designed to produce a circular composite image. The variation of the digital sub-image 128 in the area of ​​the portion shown in the digital image model 101 is a feature connected to the composite image device. This variation depends on the pattern of the digital icon image at each viewpoint and the position of that pattern relative to the pattern formed by the digital image portion 118 at each viewpoint.

[0091] Figure 8B Close-up views of some structures of the digital image model 101 are shown. Here it can be seen that the digital image object 117 of the digital image unit 116 is composed of digital sub-images 128 of each digital image unit portion 118. Depending on its position within the digital image model 101, the digital image object 117 includes portions associated with different intended integrated composite images of varying sizes and shapes.

[0092] Synthetic images are often associated with apparent depth or height (i.e., negative depth). This is often considered an “odd” feature because the device itself is a thin, planar structure. Synthetic images that appear to float above the surface of the device or seem to be hidden within the device's support structure look unnatural at first glance. The development of this optical effect is to provide a series of small depth shifts as the viewing angle changes. The result is that the image appears to “bulge” out of the surface or further disappear into the supporting material. Since magnification and perceived depth are related to each other (according to, for example, equation (3)), this type of change in perceived depth as the viewing angle changes is referred to here as a scaling effect. This striking optical effect is useful for any type of security or aesthetic device. The scaling effect can be presented alone or in combination with other optical effects, as will be discussed further below.

[0093] Figure 9 An embodiment of a method for manufacturing a synthetic image apparatus is illustrated. In step S10, a focusing element array is provided. In step S20, an image layer is arranged near the focal length of the focusing elements in the focusing element array. Thus, a synthetic image composed of a magnified portion of the image layer becomes perceptible to the viewer. The image layer includes an image unit array, wherein each image unit is associated with a corresponding focusing element in the focusing element array. The image unit array has the same symmetry and element spacing as the focusing element array. Thus, image points at each location within an image unit cooperate with image points at corresponding locations in other image units to generate a synthetic image in an associated viewing direction. The arrangement step S20 includes a step S22 of creating a corresponding image object within each corresponding image unit in the image units. The image objects are arranged such that an animation becomes perceptible. The animation comprises a series of synthetic images that can be continuously perceived as the viewing direction changes from a first viewing direction to a second viewing direction. The image objects make each of the series of synthetic images perceptible at a corresponding (stereoscopic) perceptible depth, which varies between the synthetic images in the series.

[0094] The above method thus produces a synthetic image device. The synthetic image device includes a focusing element array and an image layer. The image layer is arranged near the focal length of the focusing elements in the focusing element array, thereby making the synthetic image, composed of a magnified portion of the image layer, perceptible to the viewer. The image layer includes an image unit array, wherein each image unit is associated with a corresponding focusing element in the focusing element array, and wherein the image unit array has the same symmetry and element spacing as the focusing element array. Thus, an image point at each location within an image unit cooperates with corresponding image points in other image units to generate an image in the associated viewing direction. Image objects make animation perceptible. Animation includes a series of synthetic images that can be continuously perceived as the viewing direction changes from a first viewing direction to a second viewing direction. Image objects make each of the series of synthetic images perceptible at a corresponding (stereoscopic) perceptible depth, which varies between the synthetic images in the series.

[0095] Since it is difficult to modify an image layer once it has been printed or embossed, it is preferable to perform any definition and possible modifications of the requested synthetic image animation, as mentioned above and discussed further below, before forming the actual image object in the image layer. In other words, in a preferred embodiment, in step S23, the requested synthetic image animation to be generated by the synthetic image device is designed and defined. The definition of the requested synthetic image animation is typically performed using mathematical geometric definitions and is viewpoint-dependent. In step S24, an array of digital image cells in a digital image model is derived, wherein each of the digital image cells includes a digital representation of the shape and position of the digital image cell. The digital image model further includes a digital description of the digital image object within the corresponding digital image cell. When a transformation is performed by operating the focus element array, the digital description of the digital image object is derived from the definition of the requested synthetic image animation. This transformation includes mapping the angular dependence of the requested appearance of the focus element surface to the positional dependence of the requested appearance of the focus element surface at the corresponding digital image cell. In other words, the content of each corresponding image object is preferably determined using a corresponding digital image object of a digital image model, wherein each digital image object is obtained by deriving a corresponding digital sub-image of a corresponding digital image unit portion of a corresponding digital image unit for each viewing direction range. Subsequently, the digital sub-images of each digital image object are preferably merged to form the corresponding digital image object. Thus, each digital image unit portion corresponds to a portion of the image object that is visible through a corresponding focusing element in the corresponding viewing direction of the final product.

[0096] In step S30, image objects are created in the image layer according to the digital image object array of the digital image model. This step is typically performed according to processes known in the prior art. Typically, such a process may include a relief tool for manufacturing a structure defined by the digital image object array according to the digital image model, and a process of relief-carving the image layer of the composite image device using the relief tool. Alternatively, such a process may include a printing tool for manufacturing a structure defined by the digital image object array according to the digital image model, and a process of printing the image layer of the composite image device using the printing tool. Further alternatives may include controlling, for example, a printhead in a laser printer based on the content of the digital image object array. All these processes of transferring a digital image object array defined by mathematical or other digital means to the physical structure of the image layer at the composite image device are known to any person skilled in the art and will not be discussed further.

[0097] In other words, in one embodiment, creating an image object in each image unit includes embossing the image object in a polymer layer on a polymer substrate that presents the focusing element, or printing the image object on the polymer substrate.

[0098] In one embodiment, creating an image object in each image unit includes forming a tool with recesses formed according to the image object to be created for embossing or printing.

[0099] In one embodiment, printing includes controlling the print head to print an image object to be created.

[0100] Alternatively, a mathematical transformation from the digital icon image to obtain subimages can be used to obtain subimages for each digital image unit portion.

[0101] Therefore, the basic procedure begins with the definition of icon images to be used in the composite image animation with depth variations, and a description of the depth behavior of such images. Thus, these images requested as part of the animation, and the requested depth behavior, are design-related inputs to the manufacturing process. This design can be provided by any external or internal process, and is therefore the target of the composite image produced by the compositing device. Once the design is set, several process steps are performed that are unrelated to the design of the image, but rather relate to the issues necessary to provide a perceptible effect of the composite image involving apparent depth dependent on the viewpoint. The first step of these steps is to mathematically or digitally transform this composite image animation into the definition of a digital image model of digital image objects, as an array of digital image cells. When defining the array of digital image cells of the digital image model, a physical image layer is created based on that digital image model. Therefore, the overall transformation and possible adaptation of the digital image objects are preferably performed in the digital scheme before any physically corresponding structure is created.

[0102] One method involves digitally defining a requested synthetic image animation, wherein the shape, color, position, orientation, and size of the digital icon image, as well as the intended perceptual depth of the synthetic image, are represented as a function of viewpoint in a digital image model. The digital icon image can continuously change its appearance for different viewing orientations. In one embodiment, the digital image model can be a mathematical transformation of the array of focusing elements of the digital icon image. Thus, each position within a digital image cell is a partial transformation of the corresponding viewpoint of the changes in the synthetic image.

[0103] In other words, the transformation converts the viewpoint dependency of the digital icon image into the positional dependency within each digital image unit of the digital image model, thereby creating the requested digital image object upon which the (physical) image object is based.

[0104] Such mathematical transformations can be performed on a simple design of the requested synthetic image animation. However, for more complex image and animation sequences, purely mathematical methods can be extremely complex and impractical. In such cases, alternative methods can be used... Figures 10A to 10I A slightly different method is used to derive the definition of a digital image object array for a digital image model.

[0105] Figures 10A to 10J It showcases different aspects of providing depth-varying animation. Figure 10A An array of digital image unit portions 118 of a digital image model 101 is shown. The positions of digital image units 116 and other digital image unit portions 118 are indicated by dashed lines. An array of digital icon images 129 is placed on the digital image unit portions 118. The relative spacing of the digital icon images 129 is adapted to produce a predetermined first apparent depth, which is associated with an array of focusing elements having a predetermined pitch. This is noteworthy because the relative positions of each digital icon image 129 and its corresponding digital image unit portion 118 are different on the surface of the digital image model 101. Registration points 130 are assigned in the array of digital icon images 129, typically within one of the digital icon images 129. A portion of the digital icon image 129 overlaps with the indicated digital image unit portion 118. Figure 10B The same situation is shown in the figure, but the non-overlapping parts of the number icon image 129 are removed, leaving a number sub-image 128 that includes a portion of the corresponding original number icon image 129.

[0106] Figure 10C Similar to Figure 10A However, for another digital image unit section 118, the array of digital icon images 129 is also adapted to produce a predetermined second apparent depth, which differs from the first apparent depth. This means that... Figure 10AIn contrast, the array pitch of the number icon image 129 is different. This is noteworthy because, compared to... Figure 10A In comparison, except for registration point 130, the positions of each number icon image 129 are different. Figure 10D The same situation is shown in the example, but the non-overlapping portions of the digit icon image 129 are removed, leaving a digit sub-image 128 that includes a portion of the corresponding original digit icon image 129. This is because the position of the current digit image unit portion 118 differs from... Figure 10A The position of the digital image unit portion will be different, so the digital sub-image 128 will be different.

[0107] Figure 10E and Figure 10F The same situation was shown, but for the third group of digital image units, section 118. Figure 10G and Figure 10H The same situation was shown, but for the fourth group of digital image units, section 118.

[0108] exist Figure 10I middle, Figure 10A , Figure 10C , Figure 10E and Figure 10G They are combined into a diagram. Figure 10J middle, Figure 10B , Figure 10D , Figure 10F and Figure 10H They are combined into a single illustration. The differences between the different groups of digital image unit portions 118 are evident, and these differences become more pronounced as the distance to the registration point 130 increases. The location of the registration point 130 corresponds to the location on the synthetic image device where a depth change causes a perceived motion perpendicular to the surface of the synthetic image device. In principle, the registration point can be assigned to any location outside the digital icon image, thereby causing the synthetic image to perform a depth change accompanied by translational motion. This can be used to simulate depth changes in non-vertical directions.

[0109] Figure 10K A large portion of the digital image model 101 is shown. A digital image unit 116, positioned at a relatively large distance 131 from the registration point 130, is magnified. In this magnified portion, it can be seen that the digital image object 117, composed of different digital sub-images 128, becomes highly distorted. The constituted digital image object 117 comprises a sheet structure unfolded over the region of the digital image unit 116. Furthermore, the structure of adjacent sheets can also be associated with different parts of the intended composite image. Due to the abrupt changes in the composite image portions, the composite image produced by this segmented thin structure is often perceived as of poor quality by the viewer. The animation of the composite image thus tends to lose its smoothness. As will be discussed further below, the preferred embodiment is limited in this sense.

[0110] In the above embodiments, the numeric icon image associated with each composite image in the series remains unchanged across the composite images in the series. However, in other embodiments, the numeric icon image associated with each composite image in the series may alternatively be modified for each of the composite images, such as by changing its shape, size, color, (horizontal) position, and / or orientation. As an example, Figures 10A to 10K The deep alteration technology can be combined with... Figure 8A The shape changes caused by image layers generated by the digital image model are combined.

[0111] As shown in the attached figures above, the sub-image for each viewing direction can be derived through the following operations:

[0112] a)

[0113] A digital pattern of digit icon image 129 is created for each composite image in this series of composite images. This digital pattern has the same symmetry as the focusing element array, and is defined at least by the pattern spacing between the repeating digit icon images. The pattern spacing is chosen to allow perception at the perceptible depth of the respective composite image, and...

[0114] b)

[0115] Based on this digital pattern, a corresponding digital sub-image 28 is obtained by digitally masking the digital pattern using a mask pattern corresponding to the digital image unit portion 118 of the corresponding viewing direction range. The perceptual depth of each synthesized image is mainly determined by the spacing of the digital icon images.

[0116] Figure 11 A preferred embodiment of step S22, which creates the image object, is shown. Step S24, which derives the digital image unit array of the digital image model, includes step S25, wherein each digital image unit is divided into multiple digital image unit portions. In step S26, digital sub-images 128 are created for the digital unit portions. These digital sub-images, together with the digital sub-images 128 of the corresponding digital unit portions of other digital image units, produce a composite image corresponding to the digital image model when they are transformed for viewing via an associated focusing element, thereby continuously changing their appearance for different viewing directions.

[0117] In step S27, which may be optional, the digital sub-images of each digital unit portion within each digital image unit are fused into a digital image object for the digital image unit. Thus, the digital image object extends across all digital unit portions of the digital image unit. This fusion can also be combined with modifications to the digital sub-images 128 near the boundaries between different digital unit portions to achieve a smooth, continuous image object without sharp structures. Then, the creation of image objects in the image layer in step S30 is performed based on the digital image objects of each digital image unit.

[0118] Figure 10L and Figure 10M This demonstrates one possible way to perform this fusion in step S27. Figure 10J The image object is used as the starting point. Multiple points can be defined in the digital image unit 116, which are then used to create spline interpolation. Figure 10L In this design, the points are selected from three types. The first type of point is the average point between adjacent digital unit sections, located at the boundary of the digital image unit section 118. The second type of point is located in the middle of each digital image unit section 118. The third type of point is located at the end of the digital image unit section 118, where the structure only reaches one side of the digital image unit section 118. These points are... Figure 10L The middle label is 121.

[0119] exist Figure 10M In this process, for each set of points within two digital image units 116, a fused digital image object 123 is created using, for example, B-spline approximation.

[0120] In one embodiment, each digital unit portion is associated with a corresponding range of viewing directions.

[0121] Figure 12 Another embodiment of a digital image model 101 for depth-animated composite images is schematically illustrated. Digital image objects of the same size give different perceived depths because the period used for the spacing between repeating digital icon images is different for each viewpoint. Specifically, the figure illustrates the different periods between repeating digital icon images 129 from different viewpoints. For simplicity, the digital icon images 129 are similar for each viewing direction. For each digital image unit portion 118, the lens array P... l The periods are of course the same, but the periods p0, p1 and p2 between adjacent number icon images 129 are different, resulting in different apparent depths, see equation (2).

[0122] The magnified digital image unit 116 is positioned at a certain distance from the registration point of the digital image model, which shows that the position of the associated digital icon image 129 differs significantly among the digital image unit portions 118. As further mentioned above, this displacement distance, denoted by D in the figure, is proportional to the distance from the registration point. For apparent depths significantly larger than the radii of the lenses in the lens array, the displacement distance D is further approximately proportional to the difference between the corresponding reciprocals of the apparent depths of the digital image unit portions 118.

[0123] In mathematics, the displacement distance D can be expressed as:

[0124]

[0125] Where B is the distance to the registration point, and d0 and d1 are the depths of the composite image of the corresponding digital image unit portion 118.

[0126] Registration point 130 is a point in a digital unit at a digital image layer, wherein digital sub-images 128 of different digital image unit portions 118 are registered with each other. In other words, within the unit where registration point 130 is located, there is no relative displacement between the digital sub-images 128 of different digital image unit portions 118.

[0127] When using animated composite images, the perceived quality of the animation is generally better when each image unit contains continuous features of the image object. Presenting an image object containing several smaller features as featuresless portions between different parts associated with different digital image unit sections typically results in a poor impression of the animation. This is because the perception of different image details jumps abruptly and frequently when the viewing direction changes, as the image portion of the image object moves between areas with and without structure. In animations with depth differences, displacement distances can help create this separation of features within the image unit. For example, as long as the image object looks... Figure 10J As shown, a clear synthetic image can be expected. However, when Figure 10K When distant image objects (i.e., image objects located at a considerable distance from the registration point) are used to generate composite images, the quality is expected to be poor.

[0128] It can be noted that the fusion according to step S27 can improve the behavior of the perceived image because it reduces the occurrence of “sharp” features in the image object and provides a generally smoother transition between different parts of the image object.

[0129] This typically means that depth animation with a larger maximum depth difference can produce pleasing perception in a smaller area compared to depth animation with a smaller depth difference. Therefore, there is a trade-off between the available depth range and the physical size of the compositing image device.

[0130] The depth range used in the animation is also important. For a given depth change, shallow depth involves larger changes in the pattern's periodicity, which in turn increases the displacement distance. This means that relatively large depth or height changes are easier to animate than depth changes close to zero. Since apparent depth and magnification are related by equation (3), this means that larger magnifications are easier to use for smooth depth animations than smaller magnifications. Preferably, for suspending composite images, a magnification greater than 25 or less than -25 is preferred, i.e., a magnification greater than 25.

[0131] The relative change in magnification also affects the perception of animation. Preferably, the change in magnification between adjacent images should not exceed 20%, and most preferably should not exceed 10%. Similarly, the change in depth between adjacent images should preferably not exceed 20%, and most preferably not exceed 10%.

[0132] For these reasons, it is difficult to arrange smooth depth animation from depth to height, and vice versa. In other words, it is preferable if the apparent depth in the animation is all positive (i.e., all depth above the compositing device) or all negative (i.e., all height above the compositing device).

[0133] However, the size of the synthesized image object is also of interest. Larger expected synthesized image objects that cover most of the image units will not be as sensitive to large displacement distances, and pleasing synthesized images may appear over larger areas.

[0134] Furthermore, the number of animation steps can affect the usable area of ​​the device. A larger number of animation steps increases the likelihood of maintaining a small displacement distance between two adjacent unit areas. This, in turn, means that the usable area of ​​the composite image device can be increased.

[0135] Multiple animation steps involve at least three different depths to create continuous depth changes rather than abrupt depth jumps. In other words, depth changes throughout the animation utilize at least three different depths. However, in typical applications, the number of depths is much larger. An animation that might use 10 to 20 different depths in a loop would be a typical example.

[0136] To provide guidance on usable range, some rules of thumb can be given. Preferably, the maximum displacement distance between adjacent digital image unit portions should be kept within 5% of the image unit diameter (or other maximum distance or characteristic measure within the unit), and / or within 10% of the width of the feature within each digital image unit portion. The maximum usable area is inversely proportional to the pitch difference between adjacent steps.

[0137] Preferably, the registration point is positioned at the center of the image synthesis device, preferably within 20% of the geometric midpoint. In this case, the displacement distance points in different directions depending on which side of the image unit is placed on the registration point. Therefore, compared to other arrangements, the distance to the registration point is minimized or at least significantly reduced, thereby minimizing or at least significantly reducing the displacement distance. Placing the registration point at a corner of the image synthesis device reduces the "useful area" to one-quarter compared to placing it in the center.

[0138] Another way to increase the perceived smoothness of depth animation is to use periodic depth variations. In periodic depth variations, the apparent depth of a feature provided at one boundary of an image cell is essentially the same as the apparent depth of a feature provided at the opposite boundary of the image cell. In other words, within a cell, the depth is first changed and then changed back to its original value (or very close to it).

[0139] Figure 13A-1 , Figure 13A-2 , Figure 13A-3 , Figure 13B-1 , Figure 13B-2 and Figure 13B-3 This section showcases parts of a digital image model of the number "5" animated at two different depths. Figures 13A-1 to 13A-3 In this context, the apparent depth on the digital image unit varies from 5 mm to 6.75 mm (below the plane of the composite image device). Figure 13A-2 and Figure 13A-3 The image shows screenshots at different coordinates (in mm), such as... Figure 13A-1 As defined in [the document / reference], the registration point is located at [location]. Figure 13A-1 The bottom left corner. When the image object represented by 150 is several millimeters away from the registration point, it starts to look strange, and depth animation is expected to deteriorate at these locations. Figures 13B-1 to 13B-3 In the process, the apparent depth changes from 5 mm to 6 mm, and then returns to 5 mm in increments of 0.25 mm, thus creating a periodic depth variation. Figure 13B-2 and Figure 13B-3 The image shows screenshots at different coordinates (in mm), such as... Figure 13B-1 As defined in [the document / reference]. Here, the registration point is also located [at / included in the document / reference]. Figure 13B-1 The bottom left corner. In this case, the image object will appear acceptable, at least within the displayed area.

[0140] As indicated above, a minor drawback of using a general monolithic image method is the potential for discontinuities when the viewpoint becomes large enough to pass through the boundaries of image units. This also relates to animation. When the viewpoint reaches an image unit boundary and moves to an adjacent image unit, it can cause discontinuities in the animation. However, this can be mitigated if the animation is of a repeatable type. In this case, the start and end images are the same. By selecting associated viewpoints such that the start angle is associated with a position within the image unit that is absolutely near the image unit boundary, and the end angle is associated with a position within the image unit that is absolutely near the relative image unit boundary, continuous animation along the image unit boundaries can be achieved.

[0141] If the animation is short, then there can certainly be multiple such animation loops within a single image unit.

[0142] In other words, in one embodiment, creating an image object in each image unit includes creating an icon image that repeats in at least a first direction. The distance between adjacent focusing elements in the first distance is an integer multiple of the repeating distance of the consecutive image objects in the first direction.

[0143] In the example above, the digital image unit is shown as a rectangle. However, other geometric shapes can also be used. Figure 14A The rectangular case is illustrated, where image units 16 cover the entire surface of the image layer. Focusing elements 22 are assumed here to have a circular shape and are also closely packed. The array of image units 16 thus has the same symmetry and element spacing as the array of focusing elements 22, even if the shapes of the elements in different arrays are different.

[0144] Figure 14B Another embodiment is shown in which the image units 16 are rectangular in shape. Nevertheless, the array itself shares a common symmetry and element spacing. This means that corresponding points within different image units have the same relationship to the corresponding focusing elements 22.

[0145] Figure 14C This is yet another embodiment. Here, the image unit 16 has a hexagonal shape and is not perfectly centered compared to the focusing element 22. However, the property that corresponding points within different image units have the same relationship with the corresponding focusing element 22 still holds true.

[0146] Figure 14DAn embodiment with image unit 16 smaller than its maximum size is shown. This means that, from certain viewpoints, the composite image animation provided by the image objects within image unit 16 disappears. Areas not covered by image unit 16 can also be used to provide other composite images or composite image animations. In other words, there may be additional arrays of image units for creating other composite images provided side-by-side in the image layer, as well as image unit 16 for the composite image animations discussed above.

[0147] In the example above, the digital image unit portion is a stripe with a rectangular shape. However, this is not mandatory, and digital image unit portions of various shapes and sizes can be used. Figure 15A Seven digital image units 116 with hexagonal symmetry are shown, which are divided into digital image unit portions 118 as hexagonal closed stripes. Figure 15B A digital image unit 116 is shown, which is divided into digital image unit portions 118 of different sizes and shapes. Dividing one digital image unit 116 into digital image unit portions 118 in a digital image model can differ from dividing another digital image unit 116 into digital image unit portions 118 in the same digital image layer model. This paves the way for adapting different digital image units 116 in different ways, for example, based on the complexity of the structure within that particular unit. The digital image unit portions 118 do not necessarily have straight edges, for example… Figure 15C As shown in the image.

[0148] The above description assumes that the digital image unit sections are placed side-by-side in contact with each other. However, slightly overlapping digital image unit sections can also be used. In this case, the digital sub-images in these overlapping areas are typically adapted to provide a smooth transition between the different digital image unit sections. Digital image unit sections separated by small gaps can also be used. In this case, there will be small-angle sectors within which no digital sub-images are associated. An alternative in this case is to insert digital sub-images between adjacent digital image unit sections as filler for uncovered areas.

[0149] Each digital image unit, and consequently each physical image unit based on the digital image units, is associated with a corresponding focusing element. If the image unit array is aligned with the focusing element array, the perceived depth is the same across the entire area of ​​the synthetic imaging device. However, if there is an unintentional or intentional misalignment between the two arrays, a particular viewpoint will select an image portion from different image unit portions on the surface of the synthetic imaging device. Thus, for different portions, the perceived image will be assigned different depths. This can be understood as a simultaneous combination of depth animation and orthopic image motion.

[0150] Another way to generate depth variations (here referred to as "pitch effect") in a synthetic image device is to provide an image object with a varying pitch p(x,y) on the (physical) image layer. The basic principle is described, for example, in EP2542423. This method can be used alone to generate different perceived depths / heights on the image layer. Local depths / heights can be represented as a function h(x,y) directly related to the local pitch p(x,y). Contrary to the main technique disclosed herein, the device does not need to be tilted to generate these depth / height variations; rather, they appear at different locations on the surface. However, the two techniques can be used in combination.

[0151] In one embodiment of the combination, the animation steps consist of a series of images presenting different pitch effects. If the compositing device is rotated (i.e., the selected viewpoint is changed), the local depth / height changes according to a function (h1(x,y), h2(x,y),...) of the different images. In other words, the depth / height in this series of composite images is given by h(x,y,θ), where θ is the viewpoint.

[0152] Another surprising effect of the composite image referred to here as the "polarity effect" is that the polarity of a composite image is inverted when the composite image device is tilted (i.e., by changing the viewing direction). In this case, the difference in the content of adjacent image unit portions lies in the characteristic region 11 ( Figure 1A ) and region 11B (which has no specific characteristics) Figure 1A The image is inverted. This effect can be easily combined with the depth variations mentioned above.

[0153] The number of unit segments for a pure polarity effect is typically two, but can be higher, especially when combined with depth variation effects. For example, a greater number of unit segments can be used to increase the "speed" of the transition, i.e., the number of transitions per angular unit.

[0154] For polarity effects, the so-called print density associated with each synthesized image is an important parameter. The print density of the synthesized image is defined as the region with characteristics 11( Figure 1A The ratio between the total area covered by the image layer associated with the synthesized image and the total area covered by the image layer associated with the synthesized image.

[0155] If the print density of the composite image is n%, then the print density of the same composite image with the polarity reversed is (100-n)%. For example, reversing the polarity of an image with a print density of 47% will produce an image with a print density of 53%.

[0156] To achieve a striking polar effect that is easily identifiable, a large variation in print density is desirable. For a polar effect, the difference between print densities is preferably at least 40% (i.e., a variation from 30% to 70% or vice versa), more preferably at least 60% (from 20% to 80% or vice versa), and most preferably 80% (from 10% to 90% or vice versa).

[0157] In some advanced examples, polarity switching can be restricted to certain adjacent steps in a composite image animation, including changes in the shape, position, orientation, and size of a digital icon image. For example, scaling effects can employ one or more polarity variations to create a stronger visual effect. For scaling effects, such as composite images with the maximum magnification, the polarity can be inverted.

[0158] Of course, without inverting the polarity of the composite image, a striking effect related to significant changes in print density between images can be obtained. This effect is referred to here as "color shift." In this case, when the composite image device is tilted, the contents of adjacent image units simply produce different images with different print densities. By selecting a first color for printing and possibly a second color for the background layer covering the entire image layer, a color shift can be obtained between images as a result of changes in print density.

[0159] The number of unit parts for a color shift effect is at least two. For example, different images can be transformed into dense text with a very light design.

[0160] Similarly, to achieve a striking effect that is easily recognizable, it is desirable to vary the print density significantly. For color shift effects, the difference between print densities is preferably at least 40% (i.e., a variation from 30% to 70% or vice versa), more preferably at least 60% (from 20% to 80% or vice versa), and most preferably 80% (from 10% to 90% or vice versa).

[0161] For polarity effects, color shift effects can be limited to certain adjacent steps in a composite image animation, including changes in the shape, position, orientation, and size of digital icon images. For example, scaling effects can employ one or more color shifts to create a stronger visual impact.

[0162] The above embodiments should be understood as illustrative examples of the present invention. Those skilled in the art will understand that various modifications, combinations, and changes can be made to the embodiments without departing from the scope of the invention. Specifically, where technically possible, different partial solutions from different embodiments can be combined in other configurations. However, the scope of the invention is defined by the appended claims.

Claims

1. A method for manufacturing a synthetic image device, the method comprising the following steps: - Provides a focused element array (20); - An image layer (10) is arranged near the focal length (d) of the focusing element (22) in the focusing element array (20), thereby making the composite image composed of the magnified portion of the image layer perceptible to the viewer (2). The image layer (10) includes an array (7) of image units (16), wherein each image unit (16) is associated with a corresponding focusing element (22) in the focusing element array (20), and wherein the element distance of the array (7) of image units (16) is the same as the element distance of the focusing element array (20). The step of arranging the image layer (10) includes creating a corresponding image object (12) in each corresponding image unit in the image unit (16), the image object (12) making the animation perceptible, the animation including a series of composite images that can be continuously perceived when the viewing direction (3) changes from a first viewing direction to a second viewing direction, wherein these image objects make each of the series of composite images perceptible at a corresponding depth that varies between the composite images in the series of composite images; The creation of the corresponding image object (12) includes creating a pattern of icon images in an image unit portion associated with the corresponding viewing direction, the pattern being defined at least by the pattern spacing between repeating icon images, the pattern spacing enabling the perception of the corresponding synthetic image at the corresponding depth; The animation utilizes at least three different depths to create varying depths; and Among them, the magnification difference between adjacent images is less than 20%.

2. The method according to claim 1, characterized in that, The content of each corresponding image object (12) is determined using a corresponding digital image object of a digital image model, wherein each digital image object is obtained by deriving a corresponding digital sub-image (128) of a corresponding digital image unit portion of a corresponding digital image unit for each viewing direction and then merging the associated digital sub-images (128) of each digital image object to form the corresponding digital image object, wherein each digital image unit portion corresponds to a portion of the image object (12) that can be seen through the corresponding focusing element (22) in the corresponding viewing direction.

3. The method according to claim 2, characterized in that, The sub-image for each viewing direction is derived through the following operations: a) Create a digital pattern for each composite image in the series of composite images, the digital pattern being defined at least by the pattern spacing between the repeating digital icon images, the pattern spacing being selected such that it is perceptible at the perceptible depth of the respective composite image, and b) Based on the digital pattern, these corresponding digital sub-images are obtained by digitally masking the digital pattern using a mask pattern corresponding to the digital image unit portion of the corresponding viewing direction (128).

4. The method according to claim 3, characterized in that The icon image associated with each composite image in the series of composite images remains unchanged across the composite images in that series, or The icon image associated with each of the series of composite images has been modified for each of the composite images by changing its shape, size, color, lateral position, and / or rotation.

5. The method according to claim 1, characterized in that, The depth change throughout the animation is a unidirectional depth change that begins at the first depth and ends at the second depth.

6. The method according to claim 1, characterized in that, The depth change throughout the animation is a two-way depth change that starts at the first depth, changes to the second depth, and then returns to the first depth.

7. The method according to claim 5 or 6, characterized in that, Both the first depth and the second depth can be perceived as being in front of the image layer, or both can be perceived as being behind the image layer.

8. The method according to claim 5 or 6, characterized in that, The first depth and the second depth together define the average depth between the first depth and the second depth, wherein the depth variation between any neighboring composite images in the series of composite images is less than 10% of the average depth.

9. The method according to claim 1, characterized in that, The magnification of the image object is greater than 25.

10. The method according to claim 1, characterized in that The magnification difference between adjacent images is less than 10%.

11. The method according to claim 1, characterized in that, The depth variation between adjacent images is less than 20%.

12. The method according to claim 1, characterized in that, The maximum displacement distance between corresponding image object points in adjacent digital image units should be kept within 5% of the image unit diameter.

13. The method according to claim 1, characterized in that, The maximum displacement distance between corresponding image object points in adjacent digital image unit sections should be kept within 10% of the width of the feature within each digital image unit section.

14. The method according to claim 11, characterized in that, The registration point of the image object is located within 20% of the geometric midpoint of the synthesized image device.

15. The method according to claim 1, characterized in that, Creating an image object (12) in each image unit (16) includes embossing the image object (12) in a polymer layer on a polymer substrate on which the focusing element (22) is presented, or printing the image object (12) on the polymer substrate on which the focusing element (22) is presented.

16. The method according to claim 15, characterized in that, The creation of an image object (12) in each of the image units (16) includes forming a tool for the relief or printing with a recess formed according to the image object (12) to be created.

17. The method according to claim 15 or 16, characterized in that, The printing process includes controlling the print head to print the image object (12) to be created.

18. A synthetic image apparatus (1), comprising: -Focusing element array (20); as well as -Image layer (10); The image layer (10) is arranged near the focal length (d) of the focusing element (22) in the focusing element array (20), thereby making the composite image composed of the magnified portion of the image layer (10) perceptible to the viewer (2). The image layer (10) includes an array (7) of image units (16), wherein each image unit (16) is associated with a corresponding focusing element (22) in the focusing element array (20), and wherein the element distance of the array (7) of image units (16) is the same as the element distance of the focusing element array (20). Each image unit (16) includes an image object (12); and The image objects (12) make the animation perceptible, the animation comprising a series of composite images that can be continuously perceived when the viewing direction (3) changes from a first viewing direction to a second viewing direction, wherein these image objects make each of the series of composite images perceptible at a corresponding depth that varies between the composite images in the series of composite images; The image object (12) includes a pattern of icon images in an image unit portion associated with a corresponding viewing direction, the pattern being defined at least by a pattern spacing between repeating icon images, the pattern spacing enabling the perception of the corresponding synthetic image at the corresponding depth; The animation utilizes at least three different depths to create varying depths; and Among them, the magnification difference between adjacent images is less than 20%.

Images