Imaging film based on fresnel lens structured micro-graphic array structure
The imaging film using Fresnel lens-type micro-image array structure solves the problems of complex manufacturing process and high cost in existing anti-counterfeiting film technology, and achieves an easily identifiable and highly efficient anti-counterfeiting effect. It has ultra-thin flexibility and high-contrast three-dimensional images, and is suitable for the field of visual anti-counterfeiting.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- SIMAX SHANGHAI CO LTD
- Filing Date
- 2026-01-21
- Publication Date
- 2026-07-30
AI Technical Summary
Existing anti-counterfeiting film technology is complex and costly, making it difficult to achieve easily identifiable and efficient anti-counterfeiting effects. Furthermore, the widespread application of laser holographic anti-counterfeiting technology has led to its technological failure.
An imaging film employing a Fresnel lensing micro-image array structure includes a transparent film substrate, a composite structure micro-focusing element array layer, and a reflective film layer. By performing Fresnel lensing on the micro-image array, a Fresnel lensing micro-image array structure is formed. Combined with an ultraviolet adhesive layer and a reflective film layer, a bright effect for stereoscopic images is achieved.
An ultra-thin flexible imaging film has been developed, which has a high-contrast stereoscopic image effect, is difficult to counterfeit, reduces production costs, and is widely used in the field of visual anti-counterfeiting.
Smart Images
Figure CN2026073875_30072026_PF_FP_ABST
Abstract
Description
Imaging thin films based on Fresnel lensing micro-image array structures Technical Field
[0001] This invention relates to the field of optical anti-counterfeiting technology, and in particular to an imaging thin film based on a Fresnel lens-like micro-image array structure. Background Technology
[0002] In recent years, counterfeit and substandard goods have proliferated in my country's markets, including various brand-name liquors, cigarettes, food, beverages, pharmaceuticals, health products, cosmetics, detergents, clothing, shoes, film, medical devices, steel, cement, chemical raw materials, fertilizers, pesticides, seeds, auto parts, televisions, and more. From a public safety perspective, there are also large quantities of counterfeit banknotes, stamps, various securities, resident identity cards, household registration books, graduation certificates, qualification certificates, official seals, and so on. The sheer variety, wide distribution, and severe consequences of counterfeit and substandard goods are truly alarming. Counterfeit banknotes and various identity and qualification documents pose the most serious threat to society. Therefore, it is crucial to utilize scientific and technological means to protect high-quality brand-name goods and eliminate counterfeit and substandard products in order to prevent counterfeiting.
[0003] Common anti-counterfeiting technologies include printing, watermarking, laser holography, and color-changing inks. Printing and watermarking are easily copied and counterfeited through digital photography, scanning, and photocopying. In recent years, various types of color-changing inks have been developed, such as thermochromic, photochromic, and fluorescent inks. Color-changing inks must be combined with other technologies to achieve their anti-counterfeiting function. Laser holography, based on the principles of holographic imaging and its colorful flashes, dynamic effects, and three-dimensionality, has attracted widespread attention and was once considered the most advanced and cost-effective technology. However, with the widespread application of holography in tickets, trademarks, and packaging, many manufacturers have acquired the capability to produce holographic products, plunging laser holographic anti-counterfeiting technology into crisis. Therefore, there is an urgent need to find a new generation of mass-market anti-counterfeiting technology that is technologically advanced, low-cost, and easily identifiable.
[0004] Chinese invention patent CN103236222B discloses an anti-counterfeiting security film based on the principle of integrated imaging and with dynamic stereoscopic effect, including a microlens array layer and a unit image array layer. The unit image array layer includes multiple unit images storing image information of the target scene from different perspectives. The microlens array layer includes microlenses that are set one-to-one with the unit images and used to image the unit images. However, this patent is based on a transparent medium layer, with a microlens array and a micro-image array on both sides, which is a two-layer structure. This makes the process complicated and the cost high. Summary of the Invention
[0005] In order to overcome the shortcomings of the prior art, this invention proposes an imaging thin film based on a Fresnel lens-like micro-image array structure.
[0006] An imaging thin film based on a Fresnel lensed micro-image array structure according to the present invention includes: a transparent thin film substrate; a composite structure micro-focusing element array layer disposed on one surface of the transparent thin film substrate, comprising a plurality of composite structure micro-focusing element units, each composite structure micro-focusing element unit being obtained by Fresnel lensing the micro-image array to form a Fresnel lensed micro-image array structure, with an ultraviolet adhesive layer between adjacent composite structure micro-focusing element units, the ultraviolet adhesive layer being higher than the Fresnel lensed micro-image array structure; and a reflective film layer covering the surface of the Fresnel lensed micro-image array structure.
[0007] Preferably, there is no optical interface between the transparent thin film substrate and the composite structure micro-focusing element array layer.
[0008] Preferably, the plurality of composite structure micro-focusing element units are arranged in a cellular array, a periodic regular arrangement, or an irregular non-periodic random arrangement.
[0009] Preferably, the period of the composite structure micro-focusing element array layer is 0.1 mm, and the structural depth is less than 10 micrometers.
[0010] Preferably, the microtext array includes multiple microtext units, each of which is the image to be presented.
[0011] Preferably, the microtext unit includes microtext strokes and / or images, arranged in a dense or sparse honeycomb pattern, a square pattern, or other periodic regular arrangement, or an irregular non-periodic random arrangement, thereby forming a microtext array.
[0012] Preferably, the composite structure micro-focusing element array layer is obtained in the following manner:
[0013] After aligning the microtext array with the Fresnel microlens array, the corresponding Fresnel microlens array structure is fabricated only in the microtext array region using photolithography, i.e., the microtext array is Fresnel-lensed, while other regions retain a higher UV adhesive layer than the composite microfocusing element array, so that the Fresnel-lensed microtext array structure is presented in the UV adhesive layer pits.
[0014] Preferably, by controlling the structural thickness of the composite structure micro-focusing element array layer and the radius of curvature of the structural surface, the actual imaging distance is within ±20% of the optimal imaging distance.
[0015] Preferably, the reflective film is an aluminum film.
[0016] Preferably, the thickness of the reflective film is 20 nm to 100 nm.
[0017] The beneficial effects of this invention are:
[0018] 1. The imaging thin film in this invention has a wide viewing angle and thin thickness. The Fresnel microlens array and the micro-image array form a composite structure, which optimizes the process flow, reduces production costs, and enables thin-film imaging devices with ultra-thin and flexible characteristics.
[0019] 2. The imaging film of the present invention, through the combined action of the composite structure micro-focusing element array layer and the reflective film layer, and the micro-image array composed of Fresnel lenses, reflects the incident light, thus providing a high-contrast, bright stereoscopic image.
[0020] 3. Each composite structure micro-focusing element in this invention is a combination of Fresnel microlens array and micro-image array with logical processing. The image structure is hidden in the Fresnel array structure, which has the characteristics of being extremely difficult to manufacture and impossible to imitate.
[0021] 4. This invention has only one layer of composite structure micro-focusing element array on a transparent thin film substrate, eliminating the need to consider interface reflection and resulting in high imaging clarity.
[0022] 5. The present invention has a wide range of applications and is valuable in fields such as visual anti-counterfeiting. For example, it can be used for product markings, labels, or billboards. Attached Figure Description
[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments in conjunction with the following drawings, wherein:
[0024] Figure 1 is a schematic diagram of an imaging thin film based on a Fresnel lens micro-image array structure according to a preferred embodiment of the present invention.
[0025] Figure 2 is a schematic diagram of a virtual stereoscopic Moiré image established using the Bagua Taiji diagram as an example according to a preferred embodiment of the present invention.
[0026] Figure 3 is a schematic diagram of the imaging principle of the Fresnel lens-based micro-image array structure according to a preferred embodiment of the present invention.
[0027] Figure 4 is a schematic diagram of the unit structure in a portion of the Fresnel lens-based micro-image array according to a preferred embodiment of the present invention.
[0028] Figure 5 is a flowchart of the method for preparing an imaging thin film based on a Fresnel lens micro-image array structure according to a preferred embodiment of the present invention. Detailed Implementation
[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0030] Figure 1 is a schematic diagram of an imaging thin film based on a Fresnel lensed micro-image array structure according to a preferred embodiment of the present invention. As shown in Figure 1, the imaging thin film of the present invention includes: a transparent thin film substrate 24; a composite structure micro-focusing element array layer disposed on one surface of the transparent thin film substrate 24, comprising multiple composite structure micro-focusing element units, each composite structure micro-focusing element unit being obtained by Fresnel lensing the micro-image array to form a Fresnel lensed micro-image array structure 21, with an ultraviolet adhesive layer 23 between adjacent composite structure micro-focusing element units, the ultraviolet adhesive layer 23 being higher than the Fresnel lensed micro-image array structure 21; and a reflective film layer 22 covering the surface of the Fresnel lensed micro-image array structure. Preferably, the transparent thin film substrate 11 can be made of PET material. The ultraviolet adhesive layer 23 can be a UV adhesive layer.
[0031] In each preferred embodiment, the aperture of each unit in the composite structure microfocusing element array layer is between 25 and 250 micrometers. Each unit is arranged in a periodic, regular pattern such as a dense or sparse honeycomb arrangement or a square arrangement, or in an irregular, non-periodic, random arrangement. The period of the composite structure microfocusing element array layer is between 0.05 mm and 0.6 mm, and the structural depth is less than 10 micrometers.
[0032] In each preferred embodiment, the microtext array comprises multiple microtext units, each of which is the desired image to be presented. The microtext unit includes microtext strokes and / or images, arranged in a dense or sparse honeycomb pattern, a square pattern, or other periodic regular arrangement, or an irregular non-periodic random arrangement, thereby forming the microtext array. Figure 2 is a schematic diagram of a moiré image established using the Bagua Taiji diagram as an example according to a preferred embodiment of the present invention. If the desired image is the Bagua Taiji diagram, then the microtext unit is the Bagua Taiji diagram. This image is a virtual three-dimensional object image suitable for a Fresnel lens-enhanced microtext array structure located in an ultraviolet gel pit. Through the imaging film of the present invention, a three-dimensional image can be observed where the Taiji diagram floats relative to the film surface, and the Bagua diagram sinks relative to the film surface. The microstructures of the Taiji diagram and the Bagua diagram are designed according to the moiré imaging principle, respectively forming the visual effects of floating and sinking.
[0033] In each preferred embodiment, the composite structure micro-focusing element array layer is obtained in the following manner:
[0034] After aligning the micro-image array with the Fresnel microlens array, the corresponding Fresnel microlens array structure 21 is fabricated only in the micro-image array area (within the image area) using photolithography, that is, the micro-image array is Fresnel-lensed, while other areas retain a higher UV adhesive layer 23 than the composite structure micro-focusing element array, so that the Fresnel-lensed micro-image array structure 21 is presented in the pit of the UV adhesive layer 23.
[0035] In each preferred embodiment, by controlling the structural thickness of the composite micro-focusing element array layer and the radius of curvature of the structural surface, the actual imaging distance is kept within ±20% of the optimal imaging distance. Preferably, the structural thickness is 25 micrometers to 250 micrometers, and the radius of curvature of the surface is 12.5 micrometers to 125 micrometers. This allows the width of the serrations in the Fresnel lens to adapt to grayscale lithography resolution and provides good imaging performance.
[0036] In each preferred embodiment, the reflective film 13 is composed of an optical thin film with reflective properties, such as metallic materials including aluminum, nickel, silver, and chromium, and their alloys. Preferably, the thickness of the reflective film 13 is 20 nm to 200 nm. In other preferred embodiments, the reflective film 13 may also be composed of a multilayer film system of non-metallic materials, such as zinc oxide, silicon dioxide, magnesium fluoride, and titanium dioxide.
[0037] In each preferred embodiment, there is no optical interface between the transparent thin film substrate 11 and the composite structure micro-focusing element array layer, that is, when light passes through one layer to enter the other layer, no reflection occurs.
[0038] In each preferred embodiment, the depth (thickness) of the imaging film of the present invention is between 1 micrometer and 10 micrometers.
[0039] Through the imaging thin film structure shown in Figure 1 of this invention, a bright stereoscopic image can be observed with the naked eye. Figure 3 is a schematic diagram of the imaging principle based on the Fresnel lens-based micro-image array structure of a preferred embodiment of this invention. Since the ultraviolet adhesive layer 23 and the transparent thin film substrate 24 (PET substrate) are light-transmitting, the background outside the micro-image structure is transparent to the human eye. When light is incident on the reflective film on the surface of the Fresnel lens structure, it is reflected into the human eye. Since the micro-image array is still designed according to the principle of moiré imaging, the reflected light presents a bright image that can be seen by the human eye.
[0040] Figure 4 is a schematic diagram of the unit structure in a portion of the Fresnel lens-based micro-image array according to a preferred embodiment of the present invention. As shown in Figure 4, the unit structures (Fresnel lens-based micro-image units) are arranged in a honeycomb pattern. The width of each unit structure is 40 micrometers. Figure 4 shows that within each unit, the image area is the Fresnel lens area, and the white area is the area without image, which is the ultraviolet adhesive layer.
[0041] Figure 5 is a flowchart of the fabrication method of the imaging thin film based on the Fresnel lens-shaped micro-image array structure according to a preferred embodiment of the present invention. The fabrication method includes the following steps:
[0042] Step a: Apply photoresist 142 onto the substrate (transparent thin film substrate) 141.
[0043] Step b involves fabricating the composite micro-focusing element array layer 143 using grayscale maskless photolithography. In this step, after aligning the micro-image array with the Fresnel microlens array, the corresponding Fresnel microlens array structure is fabricated only in the micro-image array region (within the image area) using photolithography, i.e., the micro-image array is Fresnel-lensed, while other areas retain a photoresist layer higher than the composite micro-focusing element array, thus revealing the Fresnel-lensed micro-image array layer within the recesses of the photoresist layer. Specifically, based on the grayscale image of the imaging thin film structure design according to the present invention, the composite micro-focusing element array structure is formed in one step using photolithography.
[0044] Step c: The composite micro-focusing element array mold 147 is transferred using ultraviolet nanoimprint technology.
[0045] Step d: Using the mold prepared in step S3, the composite micro-focusing element array of UV adhesive material is replicated.
[0046] Step e: A reflective film layer 146 is deposited on the surface of the structure formed in step S4. Preferably, the reflective film is an aluminum film.
[0047] Step f involves scraping a protective liquid 144 into the grooves of the UV adhesive layer on the sample surface using a method similar to scraping ink, thereby covering the graphic structure within the grooves.
[0048] In step g, the surface of the sample is rinsed with sodium hydroxide solution 145, which washes away the aluminum film on the surface of the UV adhesive layer. However, the aluminum film on the surface of the micro-texture array structure is not in contact with the sodium hydroxide solution due to the coverage of the protective liquid, so this part of the aluminum film reflective layer is retained.
[0049] Step h involves forming an aluminum film reflective layer 146 on the surface of the Fresnel lensed micro-image array structure using the zero-to-zero aluminum washing method described above, thereby producing the imaging thin film based on the Fresnel lensed micro-image array structure of the present invention.
[0050] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention, which is defined by the claims and their equivalents.
Claims
1. An imaging thin film based on a Fresnel lens-like micro-image array structure, characterized in that, include: Transparent film substrate; A composite structure micro-focusing element array layer is disposed on one surface of the transparent thin film substrate, including multiple composite structure micro-focusing element units. Each composite structure micro-focusing element unit is obtained by Fresnel lensing a micro-image array, thereby forming a Fresnel lensed micro-image array structure. A photoresist layer is provided between adjacent composite structure micro-focusing element units, and the photoresist layer is higher than the Fresnel lensed micro-image array structure. as well as, A reflective film layer is applied to the surface of the Fresnel lens-like microtext array structure.
2. The imaging thin film based on the Fresnel lens-like micro-image array structure according to claim 1, characterized in that, There is no optical interface between the transparent thin film substrate and the composite structure micro-focusing element array layer.
3. The imaging thin film based on the Fresnel lens-like micro-image array structure according to claim 2, characterized in that, The multiple composite structure micro-focusing element units are arranged in a cellular array, a periodic regular arrangement, or an irregular non-periodic random arrangement.
4. The imaging thin film based on the Fresnel lens-like micro-image array structure according to claim 3, characterized in that, The composite structure micro-focusing element array layer has a period of 0.1 mm and a structural depth of less than 10 micrometers.
5. The imaging thin film based on the Fresnel lens-like micro-image array structure according to claim 1, characterized in that, The microtext array comprises multiple microtext units, each of which is the image to be presented.
6. The imaging thin film based on the Fresnel lens-like micro-image array structure according to claim 5, characterized in that, The microtext unit includes microtext strokes and / or images, arranged in a dense or sparse honeycomb pattern, a square pattern, or other periodic regular arrangement, or an irregular non-periodic random arrangement, thereby forming a microtext array.
7. The imaging thin film based on the Fresnel lens-like micro-image array structure according to claim 6, characterized in that, The composite structure micro-focusing element array layer is obtained through the following method: After aligning the microtext array with the Fresnel microlens array, the corresponding Fresnel microlens array structure is fabricated only in the microtext array region using photolithography, i.e., the microtext array is Fresnel-lensed, while other regions retain a higher UV adhesive layer than the composite microfocusing element array, so that the Fresnel-lensed microtext array structure is presented in the UV adhesive layer pits.
8. The imaging thin film based on the Fresnel lens-like micro-image array structure according to claim 1, characterized in that, By controlling the structural thickness of the composite micro-focusing element array layer and the radius of curvature of the structural surface, the actual imaging distance is kept within ±20% of the optimal imaging distance.
9. The imaging thin film based on the Fresnel lens-like micro-image array structure according to claim 1, characterized in that, The reflective film is an aluminum film.
10. The imaging thin film based on the Fresnel lens-like micro-image array structure according to claim 9, characterized in that, The thickness of the reflective film is 20 nm to 100 nm.