Preparation method of multicolor three-dimensional anti-counterfeiting film and multicolor three-dimensional anti-counterfeiting film

Abstract

The invention provides a preparation method of a multicolor three-dimensional anti-counterfeiting film and the multicolor three-dimensional anti-counterfeiting film. The preparation method comprises the following steps: preparing a micro-lens layer on one side of a substrate layer; carrying out the following steps on the other side of the substrate layer: selecting image-text structure layer molds with corresponding colors according to the sequence, preparing corresponding image-text structure layers, and filling ink with corresponding colors; the operation is repeated until preparation of all the image-text structure layers is completed; the preparation method of the color image-text structure layer mold comprises the following steps: designing a true-color three-dimensional real object image, and extracting a corresponding color channel from the true-color three-dimensional real object image according to the color of a color image-text structure layer to obtain a single-color three-dimensional real object image; presetting parameters; correcting the two-dimensional image according to preset parameters to obtain an image-text under the micro-lens layer; and overlapping the image-text to obtain a front view of the color image-text structure layer. According to the preparation method and the multicolor three-dimensional anti-counterfeiting film, the imitation difficulty of the anti-counterfeiting film is enhanced, and the problem that the anti-counterfeiting film is easily copied and counterfeited is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of optical thin films, and particularly relates to a method for preparing a multi-color three-dimensional anti-counterfeiting film and a multi-color three-dimensional anti-counterfeiting film. Background Art

[0002] Stereoscopic parallax matching is a technique for obtaining three-dimensional information from a real scene. In a common stereoscopic parallax matching system, two cameras simultaneously capture two-dimensional images of a three-dimensional object. Since the positions of each camera are different, the two images have different perspective geometric relationships. The difference in perspective geometric relationships can be analyzed through image processing to obtain three-dimensional spatial information. This difference is the parallax. Hardware-wise, a common stereoscopic parallax matching system requires two or even more cameras, which are large in size and not suitable for mobile devices.

[0003] Currently, the structure of a new type of light field computational imaging device is characterized by being able to generate a single monochromatic three-dimensional image in space. In the stereoscopic display technology based on light field computational imaging, there is still a problem of depth of field distortion. The purpose of light field computational imaging technology is to display the three-dimensional image of an object. Therefore, not only the height information and width information of the object need to be displayed, but also the depth information of the object needs to be displayed. So the depth of field of the three-dimensional image has a very important impact on its display effect. In light field computational imaging, the plane with the best reconstruction effect is the central depth plane, and the reconstruction effect of the plane farther away from the central depth plane is less ideal, and even the synthesized image may be distorted, which is caused by insufficient depth of field. Summary of the Invention

[0004] The present application provides a method for preparing a multi-color three-dimensional anti-counterfeiting film and a multi-color three-dimensional anti-counterfeiting film to solve the problem of depth of field distortion still existing in the current stereoscopic display technology based on light field computational imaging.

[0005] In a first aspect, the present application provides a method for preparing a multi-color three-dimensional anti-counterfeiting film, and the preparation method includes:

[0006] Preparing a microlens layer on one side of a base layer.

[0007] On the other side of the base layer, perform the following operations in sequence: select a corresponding color graphic structure layer mold, prepare a corresponding graphic structure layer, and fill it with a corresponding color ink.

[0008] Repeat the above operations until all graphic structure layers are prepared;

[0009] Among them, the preparation method of the color graphic structure layer mold includes:

[0010] S1: Design a true-color three-dimensional physical image, and according to the color of the color graphic structure layer, extract the corresponding color channels of the true-color three-dimensional physical image to obtain a monochromatic three-dimensional physical image;

[0011] S2: Preset parameters, where the parameters include the aperture Q of the microlens, the period P1 of the microlens, and the focal length f of the microlens; the width W of the true-color three-dimensional real object image, the length L of the true-color three-dimensional real object image, and the theoretical minimum depth of field D of the true-color three-dimensional real object image min and the theoretical maximum depth of field D of the true-color three-dimensional real object image max ; the theoretical thickness G, the actual thickness g, and the refractive index n of the base layer

[0012] S3: The microlens layer includes a plurality of microlenses. Determine the number of microlenses in the microlens layer according to the preset parameters

[0013] S4: Divide the monochromatic three-dimensional real object image into l layers of two-dimensional images Q i , and the theoretical depth of field of each layer of two-dimensional image Q i is D i , where 0 < i ≤ l; correct the theoretical depth of field D i corresponding to the two-dimensional image to obtain a corrected depth of field D′ i . According to the corrected depth of field D′ i , correct the two-dimensional image Q i to obtain a corrected two-dimensional image Q′ i ;

[0014] S5: According to the corrected two-dimensional image Q′ i , the corrected depth of field D′ i , the theoretical thickness value G, and the refractive index n of the base layer, obtain the graphic S under the microlens layer i ;

[0015] S6: Repeat steps S4 - S5, and stack the obtained l layers of graphics S i to obtain the front view of the color graphic structure layer, where the front view is the imaging pattern of the monochromatic three-dimensional real object image under the microlens layer

[0016] S7: Prepare a mold for the color graphic structure layer according to the actual front view

[0017] In a feasible implementation manner, the color channels in step S1 include a red channel, or a blue channel, or a green channel

[0018] In a feasible implementation manner, for different graphic structure layers, the theoretical thickness value G and the actual thickness g are different

[0019] In a feasible implementation manner, when determining the number of microlenses in step S3, taking the preset minimum depth of field D min of the three-dimensional image as a reference, the number of microlenses obtained is N × M, specifically including

[0020] N = (W - 2×Δd) / D min

[0021] M = (L - 2×Δd) / D min

[0022]

[0023] In a feasible implementation manner, in the step S4, the monochromatic three-dimensional physical image is divided into l layers of two-dimensional images Q i , where the l layers of two-dimensional images Q i are of equal thickness. The first layer of two-dimensional image Q1 closest to the microlens layer has a depth of field D1, which is the theoretical minimum depth of field D min ; the lth layer of two-dimensional image D l farthest from the microlens layer has a depth of field D l which is the theoretical maximum depth of field D max .

[0024] In a feasible implementation manner, in the step S4, the depth of field D i corresponding to the two-dimensional image is corrected to obtain a corrected depth of field D' i , specifically including:

[0025] Obtain the actual minimum depth of field d min ,

[0026]

[0027] The actual maximum depth of field d max ,

[0028]

[0029] According to the theoretical minimum depth of field D min , the theoretical maximum depth of field D max , the actual minimum depth of field d min , the actual maximum depth of field d max , obtain the longitudinal magnification

[0030] Obtain the corrected theoretical depth of field D' i = D min + K×(D i - D min ).

[0031] In a feasible implementation manner, in the step S4, the two-dimensional image Q i is corrected to obtain a corrected two-dimensional image Q' i , specifically including:

[0032] The two-dimensional image Q iThe size A, according to the actual thickness g and the theoretical depth of field D i , obtain the two-dimensional image Q i The actual depth of field d i ,

[0033]

[0034] According to the actual thickness g, the corrected theoretical depth of field D′ i , obtain the two-dimensional image Q i The corrected actual depth of field d′ i ,

[0035]

[0036] According to the actual depth of field d i , the actual thickness g, and the effective unit graphic size x under the microlens, obtain the actual graphic size a’;

[0037]

[0038] According to the actual graphic size a’, the corrected actual depth of field d′ i , obtain the corrected graphic size A′;

[0039]

[0040] Enlarge or reduce the two-dimensional image Q i so that the size of the corrected two-dimensional image Q′ i is the corrected graphic size A′.

[0041] In a feasible implementation, the effective unit graphic size x under the microlens is less than or equal to

[0042] In a feasible implementation, in step S5, according to the corrected two-dimensional image Q′ i , the corrected depth of field D′ i , the theoretical thickness value G, and the refractive index n of the base layer, obtain the graphic S under the microlens layer i , specifically including,

[0043] Obtain the unit graphic under each microlens and form the graphic S i .

[0044] In a feasible implementation, step S1 includes designing a virtual occluder.

[0045] In a feasible implementation, correcting the virtual occluder includes the steps of:

[0046] S41. Divide the monochromatic three-dimensional virtual occluder image into l two-dimensional images V i , and for each two-dimensional image V i , the theoretical depth of field is Vd i , where 0 < i ≤ l; correct the theoretical depth of field Vd i corresponding to the two-dimensional image to obtain the corrected depth of field Vd′ i . According to the corrected depth of field Vd′ i , correct the two-dimensional image V i to obtain the corrected two-dimensional image V′ i ;

[0047] S51. According to the corrected two-dimensional image V′ i , the corrected depth of field Vd′ i , the theoretical thickness value G, and the refractive index n of the base layer, obtain the occluding graphic Sv under the microlens layer i ; Perform a NAND operation on the recorded graphic data S i obtained in step S5 and the occluding graphic data Sv i to obtain the graphic data S′ of the final i-th layer i ;

[0048] Repeat steps S41 - S51, and stack the obtained l layers of graphics S′ i to obtain the front view of the graphic structure layer of the color band occlusion data information, and the front view is the imaging pattern of the monochromatic three-dimensional physical image under the microlens layer.

[0049] In a feasible implementation manner, the correction of the theoretical depth of field Vd i corresponding to the two-dimensional image in step S41 to obtain the corrected depth of field Vd′ i specifically includes:

[0050] Obtain the actual minimum depth of field d min ,

[0051]

[0052] the actual maximum depth of field d max ,

[0053]

[0054] According to the theoretical minimum depth of field D min , the theoretical maximum depth of field D max , the actual minimum depth of field d min , the actual maximum depth of field d max , obtain the longitudinal magnification

[0055] Obtain the corrected theoretical depth of field Vd′ i = D min + K×(Vd i - D min )

[0056] In a feasible implementation, in step S41, the two-dimensional image V i is corrected to obtain the corrected two-dimensional image V′ i , specifically including:

[0057] The size B of the two-dimensional image V i , according to the actual thickness g and the theoretical depth of field Vd i , obtain the actual depth of field vd i of the two-dimensional image V i ,

[0058]

[0059] According to the actual thickness g and the corrected theoretical depth of field Vd′ i , obtain the corrected actual depth of field vd′ i ′ of the two-dimensional image V i ′,

[0060]

[0061] According to the actual depth of field vd i , the actual thickness g, and the effective unit graphic size x under the microlens, obtain the actual graphic size b′;

[0062]

[0063] According to the actual graphic size b′ and the corrected actual depth of field vd′ i , obtain the corrected graphic size B′;

[0064]

[0065] Enlarge or reduce the two-dimensional image V i so that the size of the corrected two-dimensional image V′ i is the corrected graphic size B′

[0066] In a feasible implementation, the effective unit graphic size x under the microlens is less than or equal to

[0067] Second aspect, the present application provides a multicolor three-dimensional anti-counterfeiting film, which is prepared by any one of the above-mentioned multicolor three-dimensional anti-counterfeiting film preparation methods. The multicolor three-dimensional anti-counterfeiting film includes a base layer, a lens layer disposed on one side of the base layer, and a multi-layer graphic structure layer disposed on the other side of the base layer. The graphic structure layer includes a plurality of grooves; and ink is disposed in the grooves.

[0068] In a feasible implementation manner, the inks disposed in the grooves of different graphic structure layers have different colors.

[0069] In a feasible implementation manner, the multicolor three-dimensional anti-counterfeiting film further includes a reflective layer, and the reflective layer is disposed on the side of the lens layer away from the base layer.

[0070] The beneficial effects of the present application include:

[0071] (1) In the present application, by stratifying the monochromatic three-dimensional image and correcting the depth of field and the size of the graphics and texts of each two-dimensional image layer, the three-dimensional effect of the finally presented three-dimensional image is more prominent, and at the same time, there are no problems such as depth of field distortion, distortion, and blurring, realizing three-dimensional display in a large depth of field and large viewing angle range.

[0072] (2) In the present application, by adopting a multi-layer graphic structure layer, inks of different colors are disposed in the grooves of each graphic structure layer, thereby realizing a color three-dimensional effect, and the distance between each graphic structure layer and the lens is different. When calculating, for different color channels, monochromatic three-dimensional images of different colors are extracted. For each monochromatic three-dimensional image, the depth of field and the size of the graphics and texts are corrected, so that the obtained color three-dimensional image has no problems such as depth of field distortion, distortion, and blurring.

[0073] (3) In the present application, by setting a virtual occluder, only a part of the three-dimensional physical image is presented within a specific viewing angle range, and the part of the three-dimensional physical image blocked by the virtual image is not displayed. Therefore, the copied image cannot carry all the information of the optical imaging film, thereby realizing the functions of anti-copying and irreversible reverse modeling. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] In order to more clearly illustrate the technical solutions of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, for those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts.

[0075] Figure 1 It is a schematic flow chart of the preparation method of the color graphic structure layer mold provided by the embodiment of the present application;

[0076] Figure 2 It is a schematic optical path diagram of obtaining the actual graphic size according to the two-dimensional image size provided by the embodiment of the present application;

[0077] Figure 3 This is a schematic optical path diagram for obtaining the corrected two-dimensional image size according to the actual graphic size provided by the embodiments of the present application;

[0078] Figure 4 This is a transmissive multi-color three-dimensional anti-counterfeiting film provided by the embodiments of the present application;

[0079] Figure 5 This is a reflective multi-color three-dimensional anti-counterfeiting film provided by the embodiments of the present application. Detailed implementation manners

[0080] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0081] Since the existing anti-counterfeiting technologies mainly based on two-dimensional barcodes, digital water printing, and laser labels have the risks of being unable to assign a unique identification code to products and being easily copied and counterfeited, in order to solve this problem, on the one hand, the present application provides a method for preparing a multi-color three-dimensional anti-counterfeiting film, see Figure 1 as described. Figure 1 This is a flowchart of a method for preparing a multi-color three-dimensional anti-counterfeiting film of the present application. The preparation method includes:

[0082] Prepare a microlens layer on one side of the base layer; wherein, the microlens layer can be prepared on either the upper or lower side of the base layer.

[0083] On the other side of the base layer, perform the following operations in sequence: select a corresponding color graphic structure layer mold, prepare the corresponding graphic structure layer, and fill it with the corresponding color ink.

[0084] Repeat the above operations until the preparation of all graphic structure layers is completed.

[0085] Among them, the preparation method of the color graphic structure layer mold includes:

[0086] S1: Design a true-color three-dimensional physical image. According to the color of the color graphic structure layer, extract the corresponding color channels of the true-color three-dimensional physical image to obtain a monochromatic three-dimensional physical image; in some embodiments, the color channels include a red channel, a blue channel, or a green channel.

[0087] Specifically, the color image structure is on the other side of the lens layer. It is necessary to extract the corresponding color channels from the true-color three-dimensional physical image according to the color of the true-color three-dimensional physical image. This is to convert the true-color three-dimensional physical image into a form suitable for microlens processing, that is, to decompose the true-color image into red, green, and blue (RGB) or other color channels, so as to obtain a monochromatic three-dimensional physical image.

[0088] S2: Preset parameters, where the parameters include the aperture Q of the microlens, the microlens period P1, the focal length f of the microlens; the width W of the true-color three-dimensional physical image, the length L of the true-color three-dimensional physical image, and the theoretical minimum depth of field D of the true-color three-dimensional physical image min and the theoretical maximum depth of field D of the true-color three-dimensional physical image max ; the theoretical thickness G, the actual thickness g, and the refractive index n of the base layer; where, for different graphic structure layers, the theoretical thickness value G and the actual thickness g are different.

[0089] Among them, the aperture Q of the microlens represents the size and shape of the microlens; the microlens period P1 represents the imaging effect and resolution of the microlens; the focal length f of the microlens represents the focusing ability of the microlens. The width W and length L of the true-color three-dimensional physical image are used to define the size of the image; the theoretical minimum depth of field D_min and theoretical maximum depth of field D_max of the true-color three-dimensional physical image are used to affect the clarity and depth of the image; the theoretical thickness G and actual thickness g represent the thickness and structure of the microlens. The refractive index n of the base layer represents the refraction and propagation of light in the microlens.

[0090] S3: The microlens layer includes a plurality of microlenses. According to the preset parameters, determine the number of microlenses in the microlens layer; in some embodiments, taking the preset theoretical minimum depth of field D min as a reference, the number of microlenses obtained is N×M, specifically including:

[0091] N = (W - 2×Δd) / D min

[0092] M = (L - 2×Δd) / D min

[0093]

[0094] Among them, N and M are the numbers of microlenses in the vertical and horizontal directions respectively, W is the width of the true-color three-dimensional physical image, L is the length of the true-color three-dimensional physical image, and d is the aperture of the microlens. Based on the preset parameter data in step S2, the numbers of microlenses in the vertical and horizontal directions can be determined according to the formula. And these microlenses will be used for subsequent image processing and imaging processes.

[0095] S4: Divide the monochromatic three-dimensional physical image into l two-dimensional images Q i, in some embodiments of the present application, where the l-layer two-dimensional image Q i has a uniform thickness. The first-layer two-dimensional image Q1 closest to the microlens layer has a depth of field D1, which is the theoretical minimum depth of field D min ; the l-layer two-dimensional image Q l farthest from the microlens layer has a depth of field D l which is the theoretical maximum depth of field D max .

[0096] In this embodiment, a three-dimensional physical image of a single color is divided into l layers, and each layer is a two-dimensional image with the same thickness.

[0097] The theoretical depth of field of each layer of two-dimensional image Q i is D i , where 0 < i ≤ l;; The theoretical depth of field D i corresponding to the two-dimensional image is corrected to obtain a corrected depth of field D′ i . According to the corrected depth of field D′ i , the two-dimensional image Q i is corrected to obtain a corrected two-dimensional image Q′ i .

[0098] Since each layer of two-dimensional image Q i only records the three-dimensional model information of one color, there may be a deviation between the actual depth of field and the theoretical depth of field. Therefore, it is necessary to correct the theoretical depth of field to more accurately reflect the actual depth of field. Therefore, correction processing needs to be performed on each layer. Based on the corrected depth of field D′ i , corresponding geometric or optical correction is performed on the two-dimensional image Q i . This can correct image distortion or deformation caused by depth of field errors.

[0099] Specifically, in some embodiments of the present application, the depth of field D i corresponding to the two-dimensional image is corrected to obtain a corrected depth of field D′ i , which specifically includes:

[0100] Obtain the actual minimum depth of field d min :[[]]END]]

[0101]

[0102] The actual maximum depth of field d max :[[]]END]]

[0103]

[0104] According to the theoretical minimum depth of field D min , the theoretical maximum depth of field D max, the actual minimum depth of field d min , the actual maximum depth of field d max , obtain the longitudinal magnification

[0105] Obtain the corrected theoretical depth of field D′ i = D min + K×(D i - D min ).

[0106] In some embodiments of the present application, correct the two-dimensional image Q i to obtain a corrected two-dimensional image Q′ i , specifically including:

[0107] As Figure 2 shown, for the two-dimensional image Q i with size A, according to the actual thickness g and the theoretical depth of field D i , obtain the actual depth of field d i of the two-dimensional image Q i ,

[0108]

[0109] According to the actual thickness g and the corrected theoretical depth of field D′ i , obtain the corrected actual depth of field d′ i of the two-dimensional image Q i ,

[0110]

[0111] According to the actual depth of field d i , the actual thickness g, and the effective unit graphic size x under the microlens, obtain the actual graphic size a′;

[0112]

[0113] As Figure 3 shown, according to the actual graphic size a′ and the corrected actual depth of field d′ i , obtain the corrected graphic size A′;

[0114]

[0115] Enlarge or reduce the two-dimensional image Q i so that the size of the corrected two-dimensional image Q′ i is the corrected graphic size A′.

[0116] The effective unit graphic size under the microlens (also known as "pixel size" or "pixel pitch") is one of the important parameters affecting the imaging quality of the microlens. The effective unit graphic size is usually determined by the manufacturing process and design parameters of the microlens. During the manufacturing process, parameters such as the shape, size, and spacing of the microlens need to be precisely controlled to ensure imaging quality.

[0117] In the embodiment of the present application, the effective unit graphic size x under the microlens is less than or equal to

[0118] Step S4 is to decompose the monochromatic three-dimensional real object image into multiple layers of two-dimensional images and calculate the theoretical depth of field for each layer. Then, we correct these depths of field to obtain a more accurate imaging effect. Finally, we use the corrected depth of field to correct the two-dimensional images to obtain more accurate image information.

[0119] S5: According to the corrected two-dimensional image Q' i , corrected depth of field D' i , theoretical thickness value G, refractive index n of the base layer, obtain the graphic S under the microlens layer i ; obtain the unit graphic under each microlens and form the graphic S i .

[0120] S6: Repeat steps S4 - S5, stack the obtained l layers of graphics S i to obtain the front view of the color graphic structure layer, and the front view is the imaging pattern of the monochromatic three-dimensional real object image under the microlens layer.

[0121] By repeating and stacking the previous steps, the front view of the final color graphic structure layer is obtained. This front view will show the imaging effect of the monochromatic three-dimensional real object image under the microlens layer.

[0122] S7: Prepare the mold of the color graphic structure layer according to the actual front view. It can be understood that the mold of the color graphic structure layer is prepared according to the actual front view. This mold will be used in the subsequent production process to manufacture physical products with the required color and three-dimensional effects.

[0123] In some embodiments, step S1 further includes designing a virtual occluder and correcting the virtual occluder, including the steps:

[0124] S41: Divide the monochromatic three-dimensional virtual occluder image into l layers of two-dimensional images V i , and the theoretical depth of field of each layer of two-dimensional image V i is Vd i , where 0 < i ≤ l. Divide the monochromatic three-dimensional virtual occluder image into multiple layers of two-dimensional images and calculate the theoretical depth of field for each layer. The theoretical depth of field can be used in the subsequent correction process.

[0125] Perform correction on the theoretical depth of field Vd corresponding to the two-dimensional image i to obtain a corrected depth of field Vd' i , perform correction on the theoretical depth of field of the two-dimensional image of each layer to obtain a more accurate imaging effect; according to the corrected depth of field Vd' i , correct the two-dimensional image V i to obtain a corrected two-dimensional image V' i ; Use the corrected depth of field to correct the two-dimensional image to obtain more accurate image information.

[0126] S51: According to the corrected two-dimensional image V' i , the corrected depth of field Vd' i , the theoretical thickness value G, and the refractive index n of the base layer, obtain the occluded graphic Sv under the microlens layer i ; Use the corrected two-dimensional image, corrected depth of field, theoretical thickness value, and refractive index of the base layer to calculate the occluded graphic information under the microlens layer, providing accurate data for subsequent mold preparation.

[0127] Perform a NAND operation on the recorded graphic data S i obtained in step S5 and the occluded graphic data Sv i to obtain the final graphic data S' of the i-th layer i ; Perform a logical operation (NAND operation) on the recorded graphic data and the occluded graphic data to obtain the final graphic data. This final graphic data will be used in subsequent superposition and imaging processes.

[0128] Repeat steps S41 - S51, and superimpose the obtained l-layer graphics S' i to obtain a front view of the graphic structure layer of the color band occlusion data information. The front view is the imaging pattern of the monochromatic three-dimensional real object image under the microlens layer. Repeat and superimpose the previous steps to obtain a front view of the graphic structure layer of the final color band occlusion data information. This front view will show the imaging effect of the monochromatic three-dimensional real object image under the microlens layer.

[0129] It can be understood that in the second embodiment, the processing method of the three-dimensional real object image is the same as the method steps in the first embodiment, and most of the processing methods of the three-dimensional virtual occluding object image are also the same.

[0130] In some embodiments, in step S41, perform correction on the theoretical depth of field Vd corresponding to the two-dimensional image i to obtain a corrected depth of field Vd' i , specifically including:

[0131] Obtain the actual minimum depth of field d min ,

[0132]

[0133] Actual maximum depth of field d max ,

[0134]

[0135] According to the theoretical minimum depth of field D min , the theoretical maximum depth of field D max , the actual minimum depth of field d min , the actual maximum depth of field d max , the longitudinal magnification is obtained

[0136] Obtain the corrected theoretical depth of field Vd′ i = D min + K×(Vd i - D min ).

[0137] In some embodiments, in step S41, the two-dimensional image V i is corrected to obtain a corrected two-dimensional image V′ i , specifically including:

[0138] For the size B of the two-dimensional image V i , according to the actual thickness g, the theoretical depth of field Vd i , the actual depth of field vd i of the two-dimensional image V i is obtained,

[0139]

[0140] According to the actual thickness g, the corrected theoretical depth of field Vd′ i , the corrected actual depth of field vd′ i of the two-dimensional image V i is obtained,

[0141]

[0142] According to the actual depth of field vd i , the actual thickness g, and the effective unit graphic size x under the microlens, the actual graphic size b′ is obtained;

[0143]

[0144] According to the actual graphic size b′, the corrected actual depth of field vd′ i , the corrected graphic size B′ is obtained;

[0145]

[0146] Enlarge or reduce the two-dimensional image V i so that the size of the corrected two-dimensional image V′ i is the size of the corrected graphic and text size B′.

[0147] In a feasible implementation manner, the effective unit graphic and text size x under the microlens is less than or equal to

[0148] In the second embodiment of the present application, the l-layer graphics and texts S′ obtained by processing the three-dimensional physical image and the three-dimensional virtual occluder image i are superimposed to obtain a front view of the graphic structure layer of the color band occlusion data information, so that only a part of the three-dimensional physical image is presented within a specific viewing angle range, and the part of the three-dimensional physical image occluded by the virtual image is not displayed. Therefore, the copied image cannot carry all the information of the optical imaging film, thus realizing the functions of anti-copying and non-invertible reverse modeling.

[0149] On the other hand, the present application provides a multi-color three-dimensional anti-counterfeiting film, which is prepared by the multi-color three-dimensional anti-counterfeiting film preparation method described in any one of the above. Refer to Figure 4 As shown, on the other hand, the present application provides a multi-color three-dimensional anti-counterfeiting film, which is prepared by the multi-color three-dimensional anti-counterfeiting film preparation method described above. The multi-color three-dimensional anti-counterfeiting film includes a base layer, a lens layer provided on one side of the base layer, and a multi-layer graphic structure layer provided on the other side of the base layer. The graphic structure layer includes a plurality of grooves; ink is provided in the grooves.

[0150] The multi-color three-dimensional anti-counterfeiting film in the embodiment of the present application includes a multi-layer structure. The outermost layer is a lens layer, and the lens layer is an array of plano-convex lenses with a fixed aperture, and the convex part is the outermost side; the side close to the plane of the lens layer is the base layer, which is a transparent thin film layer for controlling the distance from the graphic structure layer to the vertex of the lens. Close to the other side of the base layer, several layers of graphic structure layers are superimposed in sequence. Each graphic structure layer has grooves, and the pits are filled with ink.

[0151] In some embodiments of the present application, the ink colors provided in the grooves of different graphic structure layers are different. Continuing to refer to Figure 4 As shown, taking a three-layer graphic structure layer as an example, the ink colors filled in the grooves of different graphic structure layers are different, and a true-color three-dimensional anti-counterfeiting film can be formed by combining no less than three colors of ink.

[0152] In some embodiments of the present application, the multi-color three-dimensional anti-counterfeiting film further includes a reflective layer, and the reflective layer is provided on the side of the lens layer away from the base layer.

[0153] In some embodiments of the present application, with reference to Figure 5 as shown, Figure 5 taking the three - layer graphic structure layer as an example, the multi - color three - dimensional anti - counterfeiting film further includes a reflective layer; the reflective layer is disposed on a side of the lens layer away from the base layer. Such a multi - color three - dimensional anti - counterfeiting film with a reflective layer structure is a reflective multi - color three - dimensional anti - counterfeiting film.

[0154] The reflective layer is usually formed by adding a layer of metal or dielectric layer with a specific reflection effect on a thin - film material. The reflective layer can reflect light back to the surface of the thin film, thereby producing a specific reflection effect.

[0155] As can be seen from the above - mentioned embodiment content, the present application provides a method for preparing a multi - color three - dimensional anti - counterfeiting film and the multi - color three - dimensional anti - counterfeiting film. By correcting the depth of field and the size of the graphics of each two - dimensional image, the three - dimensional effect of the finally presented three - dimensional image is more prominent, and there are no problems such as depth - of - field distortion, distortion, and blurring. Three - dimensional display in a large depth - of - field and large viewing - angle range is realized. By adopting a multi - layer graphic structure layer and setting inks of different colors in the grooves within each graphic structure layer, a color three - dimensional effect is achieved. By setting virtual occluders, only part of the three - dimensional physical image is presented within a specific viewing - angle range, and the part of the three - dimensional physical image blocked by the virtual image is not displayed. Therefore, the copied image cannot carry all the information of the optical imaging film, thus realizing the functions of anti - copying and preventing reverse engineering and modeling.

[0156] It should be noted in the embodiments of the present application that the term "comprising", "including" or any other variant thereof is intended to cover non - exclusive inclusion, so that an institution, article or device including a series of elements not only includes those elements but also includes other elements not explicitly listed, or further includes elements inherent to such institution, article or device. Without further limitation, elements defined by the statement "including..." do not exclude the existence of additional identical elements in the institution, article or device including the elements.

[0157] Those skilled in the art will readily think of other embodiments of the present disclosure after considering the specification and practicing the disclosure herein. The present application is intended to cover any variations, uses or adaptations of the present disclosure that follow the general principles of the present disclosure and include common general knowledge or conventional technical means in the technical field not disclosed in the present disclosure. The specification and the embodiments are only regarded as exemplary, and the true scope and spirit of the present disclosure are pointed out by the following claims.

Claims

1. A method for preparing a multi-color three-dimensional anti-counterfeiting film, characterized in that, Including: Preparing a microlens layer on one side of the base layer; On the other side of the base layer, perform the following operations: in sequence, select a mold for the color graphic structure layer corresponding to the color, prepare the corresponding graphic structure layer, and fill it with the corresponding color ink; Repeat the above operations until the preparation of all graphic structure layers is completed; Among them, the preparation method of the color graphic structure layer mold includes: S1: Design a true-color three-dimensional physical image, and according to the color of the color graphic structure layer, extract the corresponding color channels of the true-color three-dimensional physical image to obtain a monochromatic three-dimensional physical image; S2: Preset parameters, where the parameters include the aperture Q of the microlens, the period P1 of the microlens, the focal length f of the microlens; the width W of the true-color stereoscopic real object image, the length L of the true-color stereoscopic real object image, and the theoretical minimum depth of field D of the true-color stereoscopic real object image min and the theoretical maximum depth of field D of the true-color stereoscopic real object image max ; the theoretical thickness G, the actual thickness g, and the refractive index n of the base layer S3: The microlens layer includes a plurality of microlenses. According to the preset parameters, determine the number of microlenses in the microlens layer; S4: Divide the monochromatic three-dimensional physical image into l layers of two-dimensional images Q i , and for each layer of two-dimensional image Q i , the theoretical depth of field is D i , where 0 < i ≤ 1; correct the theoretical depth of field D i corresponding to the two-dimensional image to obtain a corrected depth of field D' i . According to the corrected depth of field D' i , correct the two-dimensional image Q i to obtain a corrected two-dimensional image Q' i ; S5: According to the corrected two-dimensional image Q′ i , the corrected depth of field D′ i , the theoretical thickness value G, the refractive index n of the base layer, to obtain the graphic S under the microlens layer i ; S6: Repeat steps S4 - S5, and stack the obtained l layers of graphic texts S i to obtain a front view of the color graphic text structure layer, where the front view is the imaging pattern of the monochromatic three-dimensional physical image under the microlens layer; S7: Prepare the mold of the color graphic structure layer according to the actual front view.

2. The method for preparing a multicolor three-dimensional anti-counterfeiting film according to claim 1, characterized in that, The color channels in step S1 include a red channel, or a blue channel, or a green channel.

3. A method for preparing a multi-color three-dimensional anti-counterfeiting film according to claim 1, characterized in that, For different graphic structure layers, the theoretical thickness value G and the actual thickness g are different.

4. The preparation method of a multi-color three-dimensional anti-counterfeiting film according to claim 1, wherein, In step S3, the number of microlenses is determined based on the preset theoretical minimum depth of field D min as a reference, and the number of microlenses obtained is N×M, specifically including: N = (W - 2×Δd) / D min M = (L - 2×Δd) / D min 5. A method for preparing a multi-color three-dimensional anti-counterfeiting film according to claim 1, characterized in that, In step S4, the monochromatic three-dimensional real image is divided into l two-dimensional images Q i , where the l two-dimensional images Q i have equal thickness. The first two-dimensional image Q1 closest to the microlens layer has a depth of field D1, which is the theoretical minimum depth of field D min ; the lth two-dimensional image Q l farthest from the microlens layer has a depth of field D l , which is the theoretical maximum depth of field D max .

6. A method for preparing a multi-color three-dimensional anti-counterfeiting film according to claim 1, characterized in that, In the step S4, the depth of field D corresponding to the two-dimensional image i is corrected to obtain a corrected depth of field D' i , which specifically includes: Obtain the actual minimum depth of field d min , Actual maximum depth of field d max , According to the theoretical minimum depth of field D min , the theoretical maximum depth of field D max , the actual minimum depth of field d min , the actual maximum depth of field d max , the longitudinal magnification is obtained Obtain the corrected theoretical depth of field D′ i = D min + K × (D i - D min ).

7. A method for preparing a multi-color three-dimensional anti-counterfeiting film according to claim 6, characterized in that, In the step S4, the two-dimensional image Q i is corrected to obtain a corrected two-dimensional image Q' i , which specifically includes: Two-dimensional image Q i with dimension A, according to the actual thickness g and the theoretical depth of field D i to obtain the actual depth of field d of the two-dimensional image Q i i ,​ According to the actual thickness g, the corrected theoretical depth of field D′ i , obtain the two-dimensional image Q i of the corrected actual depth of field d′ i , According to the actual depth of field d i , the actual thickness g, and the effective unit graphic size x under the microlens, the actual graphic size a' is obtained; According to the actual graphic size a', the corrected actual depth of field d' i , a corrected graphic size A' is obtained; Enlarge or reduce the two-dimensional image Q i so that the size of the corrected two-dimensional image Q' i is the size A' of the corrected text and image.

8. A method for preparing a multi-color three-dimensional anti-counterfeiting film according to claim 7, characterized in that, The graphic size x of the effective unit under the microlens is less than or equal to 9. The method for preparing a multi-color three-dimensional anti-counterfeiting film according to claim 6, characterized in that, In the step S5, according to the corrected two-dimensional image Q' i , the corrected depth of field D' i , the theoretical thickness value G, the refractive index n of the base layer, the graphic S under the microlens layer is obtained i , specifically including, Obtain the unit graphics and texts under each of the micro-lenses, and form graphics and text S i 。 10. A method for preparing a multi-color three-dimensional anti-counterfeiting film according to claim 1, characterized in that, Step S1 includes designing a virtual occluder.

11. A method for preparing a multi-color three-dimensional anti-counterfeiting film according to claim 10, characterized in that, Correcting the virtual occluder includes the steps: S41. Divide the monochromatic three-dimensional virtual occluder image into l two-dimensional images V i , and for each two-dimensional image V i , the theoretical depth of field is Vd i , where 0 < i ≤ 1; correct the theoretical depth of field Vd i corresponding to the two-dimensional image to obtain a corrected depth of field Vd′ i . According to the corrected depth of field Vd′ i , correct the two-dimensional image V i to obtain a corrected two-dimensional image V′ i ; S51, according to the corrected two-dimensional image V′ i 、the corrected depth of field Vd′ i 、the theoretical thickness value G, the refractive index n of the base layer, to obtain the occluded graphic Sv under the microlens layer i ; perform a NAND operation on the recorded graphic data S obtained in step S5 i and the occluded graphic data Sv i to obtain the graphic data S′ of the final i-th layer i ; Repeat steps S41 - S51 to superimpose the obtained l - layer graphic texts S′ i to obtain a front view of the graphic structure layer with the color band occlusion data information, where the front view is the imaging pattern of the monochromatic three - dimensional physical image under the microlens layer.

12. According to the method for preparing a multi-color three-dimensional anti-counterfeiting film described in claim 11, characterized in that In the step S41, the theoretical depth of field Vd corresponding to the two-dimensional image i is corrected to obtain a corrected depth of field Vd' i , which specifically includes: Obtain the actual minimum depth of field d min , Actual maximum depth of field d max , According to the theoretical minimum depth of field D min , the theoretical maximum depth of field D max , the actual minimum depth of field d min , the actual maximum depth of field d max , the longitudinal magnification is obtained Obtain the corrected theoretical depth of field Vd′ i = D min + K × (Vd i - D min ).

13. A method for preparing a multi-color three-dimensional anti-counterfeiting film according to claim 11, characterized in that, In the step S41, the two-dimensional image V i is corrected to obtain a corrected two-dimensional image V' i , which specifically includes: Two-dimensional image V i The size B of, according to the actual thickness g, the theoretical depth of field Vd i , obtain the two-dimensional image V i The actual depth of field vd of i , According to the actual thickness g, the corrected theoretical depth of field Vd′ i , obtain the two-dimensional image V i of the corrected actual depth of field vd′ i , According to the actual depth of field vd i , the actual thickness g, and the effective unit graphic size x under the microlens, the actual graphic size b’ is obtained; According to the actual graphic size b’, the corrected actual depth of field vd’ i , the corrected graphic size B’ is obtained; Enlarge or reduce the two-dimensional image V i so that the size of the corrected two-dimensional image V' i is the size B' of the corrected text and image.

14. A method for preparing a multi-color three-dimensional anti-counterfeiting film according to claim 13, characterized in that, The graphic size x of the effective unit under the microlens is less than or equal to 15. A multicolor three-dimensional anti-counterfeiting film, characterized in that, The multi-color three-dimensional anti-counterfeiting film is prepared by the method for preparing a multi-color three-dimensional anti-counterfeiting film according to any one of claims 1 to 14. The multi-color three-dimensional anti-counterfeiting film includes a base layer, a lens layer provided on one side of the base layer, and a multi-layer graphic structure layer provided on the other side of the base layer. The graphic structure layer includes a plurality of grooves; ink is provided in the grooves.

16. A multicolor three-dimensional anti-counterfeiting film according to claim 15, characterized in that, The ink colors provided in the grooves in different graphic structure layers are different.

17. A multicolor three-dimensional anti-counterfeiting film according to claim 15, characterized in that, The multi-color three-dimensional anti-counterfeiting film further includes a reflective layer, and the reflective layer is provided on the side of the lens layer away from the base layer.

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