Fresnel micro lens array structure imaging film with micro image-text array groove

Abstract

The invention discloses a Fresnel micro-lens array structure imaging film with micro image-text array grooves. The Fresnel micro-lens array structure imaging film comprises a transparent film substrate; the composite micro-focusing element array layer consists of a plurality of composite micro-focusing element units and is arranged on one surface of the transparent film substrate; the structure of the composite micro-focusing element array layer is that a micro image-text array is superposed on the surface of a Fresnel micro-lens array for logic processing to form a Fresnel micro-lens array structure with a micro image-text array groove; and the reflecting film layer covers the surface of the composite micro-focusing element array layer. The imaging thin film is large in visual angle and thin in thickness, the Fresnel micro lens array and the micro image-text array groove form a composite structure, the technological process is optimized, the production cost is reduced, and a thin film type imaging device with ultra-thin and flexible characteristics can be achieved. According to the imaging film provided by the invention, through the combined action of the composite micro-focusing element array layer and the reflecting film layer, a dynamic image with multiple visual angles, high contrast and a black effect is provided.

Description

Technical Field

[0001] The invention relates to the technical field of optical anti-counterfeiting, and in particular to a Fresnel microlens array structure imaging film with micro-image array grooves. Background Art

[0002] In order to prevent goods from being counterfeited, it is particularly important to use scientific and technological means to protect high-quality brand-name goods and eliminate counterfeit and shoddy goods.

[0003] Common public anti-counterfeiting technologies mainly include printing, watermarking, laser holography and color-changing inks. Printing and watermarking are easy to copy and forge through digital photography, scanning, copying, etc. In recent years, people have developed many different types of color-changing inks, such as temperature-changing, light-changing and fluorescent types. Color-changing inks must be combined with other technologies to achieve anti-counterfeiting functions. Laser holographic technology has attracted widespread attention based on the principle of holographic imaging and colorful flashes, dynamics and three-dimensional effects. It was once recognized as the most advanced and cost-effective technology. However, with the widespread application of holography in the fields of tickets, trademarks, packaging, etc., many manufacturers have the ability to produce holographic products, which has put laser holographic anti-counterfeiting technology into crisis. Therefore, people are in urgent need of finding a new generation of public anti-counterfeiting technology that meets the requirements of high technology, low cost and easy identification.

[0004] Chinese invention patent CN103236222B discloses an anti-counterfeiting security film based on the principle of integrated imaging and having a dynamic three-dimensional effect, including a microlens array layer and a unit image array layer. The unit image array layer includes a plurality of unit images storing image information of target scenes at different viewing angles. The microlens array layer includes microlenses arranged in one-to-one correspondence with the unit images and used to image the unit images. However, the patent is based on a transparent medium layer, with a microlens array and a micro-image array on both sides, that is, a two-layer structure, which makes the process complicated and the cost high. Summary of the invention

[0005] In order to solve the defects of the prior art, the present invention proposes a Fresnel microlens array structure imaging film with micro-image array grooves.

[0006] The Fresnel microlens array structure imaging film having micro-image array grooves of the present invention comprises:

[0007] Transparent film substrate;

[0008] A composite micro-focusing element array layer, composed of a plurality of composite micro-focusing element units, is disposed on one surface of the transparent film substrate; the composite micro-focusing element array layer is constructed as follows: on the surface of the Fresnel micro-lens array, a micro-image array is superimposed for logic processing to form a Fresnel micro-lens array structure with micro-image array grooves; and

[0009] The reflective film layer covers the surface of the composite micro-focusing element array layer.

[0010] Preferably, there is no optical interface between the transparent film substrate and the composite micro-focusing element array layer.

[0011] Preferably, the Fresnel microlens array is composed of a plurality of lens units, the micro-image array groove is composed of a plurality of micro-image units, and the micro-image array groove corresponds to the Fresnel microlens array one-to-one, that is, each micro-image unit of the micro-image array groove corresponds to each lens unit of the Fresnel microlens array.

[0012] Preferably, each micro-image unit in the micro-image array groove is a part of the transformation image to be presented, and a plurality of micro-image units constitute a dynamic image that changes with the change of viewing angle.

[0013] Preferably, the logic processing is to form grooves on the corresponding surface of the Fresnel microlens array according to the transformation image to be presented.

[0014] Preferably, the thickness of the composite micro-focusing element array layer is less than 0.025 mm, and the depth of the groove is 1 micron to 10 microns.

[0015] Preferably, by controlling the structural thickness of the composite micro-focusing element array layer and the curvature radius of the structural surface, the actual imaging distance is within the range of ±20% of the optimal imaging distance.

[0016] Preferably, the reflective film layer is metal chromium, metal copper, metal aluminum or metal silver.

[0017] Preferably, the reflective film layer has a thickness of 20 nm to 200 nm.

[0018] Preferably, the black imaging effect of the composite micro-focusing element array layer comes from the lack of light in the pattern grooves on the surface of the Fresnel micro-lens array, which contrasts with the light reflected by the surrounding lens surfaces into the human eye, so that the human eye observes a black image.

[0019] The beneficial effects of the present invention are:

[0020] 1. The imaging film of the present invention has a large viewing angle and a thin thickness. The Fresnel microlens array and the micro-image array grooves form a composite structure, which optimizes the process flow, reduces the production cost, and can realize a film-type imaging device with ultra-thin and flexible characteristics.

[0021] 2. The imaging film of the present invention provides dynamic images with multiple viewing angles, high contrast and black effects through the combined action of the composite micro-focusing element array layer and the reflective film layer.

[0022] 3. The dynamic visual effect in the present invention does not require wearing glasses and can be seen with naked eyes, and has the advantage of forming dynamic images as the viewing angle changes.

[0023] 4. Each composite micro-focusing element in the present invention uses a partial image and a Fresnel lens structure for logical processing, so it is impossible to understand the complete image information from a single composite micro-focusing element. In addition, the Fresnel micro-lens array and the micro-graphic array are logically processed, and the graphic structure is hidden in the Fresnel array structure, which is extremely difficult to manufacture and cannot be imitated.

[0024] 5. The present invention has only one composite micro-focusing element array layer on the transparent film substrate, and there is no need to consider interface reflection, so the imaging clarity is high.

[0025] 6. The present invention has a wide range of applications and has application value in the fields of visual anti-counterfeiting, for example, it can be used for product logos, labels or billboards. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the description of the implementation methods in combination with the following drawings, among which:

[0027] Figure 1 This is a schematic diagram of a Fresnel microlens array structure imaging film with micro-image array grooves according to a preferred embodiment of the present invention.

[0028] Figure 2 This is a schematic diagram of a virtual dynamic comic strip based on the human evolution process as an example of a preferred embodiment of the present invention.

[0029] Figure 3 This is a schematic diagram of imaging of a Fresnel microlens array structure with micro-image array grooves according to a preferred embodiment of the present invention.

[0030] Figure 4It is a schematic diagram of the unit structure in a partial area of ​​a Fresnel microlens array with micro-image array grooves according to a preferred embodiment of the present invention.

[0031] Figure 5 The present invention is a flow chart of the preparation of the imaging film according to the preferred embodiment of the present invention. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] Figure 1 Schematic diagram of a Fresnel microlens array structure imaging film with micro-image array grooves according to a preferred embodiment of the present invention. Figure 1 As shown, the imaging film of the present invention comprises: a transparent film substrate 11; a composite micro-focusing element array layer, which is arranged on one surface of the transparent film substrate 11; the composite micro-focusing element array layer is constructed as follows: a micro-image array is superimposed on the surface of the Fresnel micro-lens array for logical processing to form a Fresnel micro-lens array layer 12 having a micro-image array groove 14; and a reflective film layer 13, which covers the surface of the composite micro-focusing element array layer. The transparent film substrate 11 can be a PET material. The composite micro-focusing element array layer is composed of a plurality of composite micro-focusing element units. Specifically, the Fresnel micro-lens array 12 is composed of a plurality of lens units, and the micro-image array groove 14 is composed of a plurality of micro-image units. Preferably, in the composite micro-focusing element array layer, the micro-image array groove 14 is one-to-one corresponding to the Fresnel micro-lens array 12, and is completely aligned. The one-to-one correspondence here means that each micro-image unit of the micro-image array groove 14 corresponds to each lens unit of the Fresnel micro-lens array 12.

[0034] In each preferred embodiment, the aperture of each unit of the composite micro-focusing element array layer is about 100 microns. The arrangement of each unit is a periodic regular arrangement such as a dense or sparse honeycomb arrangement, a square arrangement, or an irregular non-periodic random arrangement.

[0035] In each preferred embodiment, each micro-graphic unit in the micro-graphic array groove 14 is all or part of the image to be presented. Preferably, each micro-graphic unit in the micro-graphic array groove 14 is part of the transformed image to be presented, and a plurality of micro-graphic units form a dynamic image that changes with the change of viewing angle. Figure 2This is a schematic diagram of a virtual dynamic comic strip established by taking the human evolution process as an example in a preferred embodiment of the present invention. That is to say, if the virtual dynamic comic strip (i.e., the transformed image) is to be presented, each micro-graphic unit in the micro-graphic array groove 14 is a part of the comic strip image. Preferably, the logic processing is to form a groove on the surface of the corresponding Fresnel microlens array 12 according to the transformed image to be presented. Specifically, a groove is formed on the surface of each lens unit of the Fresnel microlens array 12 according to a polygon (contour) similar to the comic strip image. Preferably, the depth of the groove is 1 micron to 10 microns.

[0036] In each preferred embodiment, by controlling the structural thickness of the composite micro-focusing element array layer and the curvature radius of the structural surface, the actual imaging distance is within the range of ±20% of the optimal imaging distance. Preferably, the structural thickness is 25 microns to 250 microns, and the curvature radius of the surface is 12.5 microns to 125 microns. In this way, the bevel width in the Fresnel lens can adapt to the grayscale lithography resolution and has a better imaging effect.

[0037] In each preferred embodiment, the reflective film layer 13 is composed of an optical film with a reflective effect, such as a metal material, including aluminum, nickel, silver and chromium, and alloys thereof. Preferably, the thickness of the reflective film layer 13 is 20nm to 200nm. In other preferred embodiments, the reflective film layer 13 can also be composed of a multilayer film system of non-metallic materials, such as zinc oxide, silicon dioxide, magnesium fluoride and titanium dioxide.

[0038] In each preferred embodiment, there is no optical interface between the transparent film substrate 11 and the composite micro-focusing element array layer (Fresnel micro-lens array 12), that is, no reflection occurs when light passes through one layer into the other layer.

[0039] In each preferred embodiment, the depth (thickness) of the imaging film of the present invention is between 1 micron and 10 microns.

[0040] Through the present invention Figure 1 With the imaging film structure shown, people can observe black dynamic images with naked eyes. Figure 3 The schematic diagram of the imaging principle of the Fresnel microlens array structure with micro-image array grooves of the present invention. Since the lens array structure layer (i.e., UV embossing layer) and the transparent film substrate of the PET substrate are light-transmissive, the background outside the micro-image structure seen by the human eye is transparent. When the light is incident on the reflective film on the surface of the Fresnel lens structure, it is reflected and enters the human eye. However, since the micro-image array part is composed of grooves, it cannot be reflected in the direction of the Fresnel microlens array, so a black image is presented.

[0041] Figure 4FIG. 1 is a schematic diagram of a unit structure in a partial area of ​​a Fresnel microlens array with micro-image array grooves according to a preferred embodiment of the present invention. Figure 4 As shown, the unit structures (Fresnel microlens units with micro-image grooves) are arranged in a honeycomb pattern. The radius of each unit structure is 40 microns, and it has 9 groove structures, corresponding to Figure 2 In the 9 images in the virtual dynamic comic strip shown in , each groove outline is a part of the corresponding image polygon (contour), and multiple micro-image and text units can form complete image information. As the observer's perspective changes, the changing dynamic image can be seen.

[0042] Figure 5 The preparation flow chart of the imaging film of the Fresnel microlens array structure with micro-image array grooves of the present invention. First, in step a, a photoresist 131 is applied on a substrate 132. Then, in step b, a composite micro-focusing element array layer 133 is produced by using grayscale maskless photolithography technology. Here, the composite micro-focusing element array layer 133 is formed by a designed grayscale Figure 1 The grayscale image is obtained according to the structural design of the imaging film of the present invention, that is, a Fresnel microlens array structure with micro-image grooves is formed. Step c, the composite micro-focusing element array layer mold 134 is transferred by ultraviolet nano-imprinting technology. Step d, continue to copy the composite micro-focusing element array layer 135 of UV glue material. Finally, step e, a reflective film layer 136 is plated on the surface of the composite micro-focusing element array layer 135, thereby forming the imaging film of the Fresnel micro-lens array structure with micro-image array grooves of the present invention.

[0043] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. A Fresnel microlens array structure imaging film having micro-image array grooves, characterized in that: include: Transparent film substrate; A composite micro-focusing element array layer, composed of a plurality of composite micro-focusing element units, is disposed on one surface of the transparent film substrate; the composite micro-focusing element array layer is constructed as follows: on the surface of the Fresnel micro-lens array, a micro-image array is superimposed for logic processing to form a Fresnel micro-lens array structure with micro-image array grooves; and The reflective film layer covers the surface of the composite micro-focusing element array layer.

2. The Fresnel microlens array structure imaging film with micro-image array grooves according to claim 1, characterized in that: There is no optical interface between the transparent film substrate and the composite micro-focusing element array layer.

3. The Fresnel microlens array structure imaging film with micro-image array grooves according to claim 2, characterized in that: The Fresnel microlens array is composed of a plurality of lens units, the micro-image array groove is composed of a plurality of micro-image units, and the micro-image array groove corresponds to the Fresnel microlens array one by one, that is, each micro-image unit of the micro-image array groove corresponds to each lens unit of the Fresnel microlens array.

4. The Fresnel microlens array structure imaging film with micro-image array grooves according to claim 3, characterized in that: Each micro-image unit in the micro-image array groove is a part of the transformation image to be presented, and a plurality of micro-image units form a dynamic image that changes with the change of viewing angle.

5. The Fresnel microlens array structure imaging film with micro-image array grooves according to claim 4, characterized in that: The logic processing is to form grooves on the corresponding surface of the Fresnel microlens array according to the transformation image to be presented.

6. The Fresnel microlens array structure imaging film with micro-image array grooves according to claim 5, characterized in that: The thickness of the composite micro-focusing element array layer is less than 0.025 mm, and the depth of the groove is 1 micron to 10 microns.

7. The Fresnel microlens array structure imaging film with micro-image array grooves according to claim 1, characterized in that: By controlling the structural thickness of the composite micro-focusing element array layer and the curvature radius of the structural surface, the actual imaging distance is within the range of ±20% of the optimal imaging distance.

8. The Fresnel microlens array structure imaging film with micro-image array grooves according to claim 1, characterized in that: The reflective film layer is made of metal chromium, metal copper, metal aluminum or metal silver.

9. The Fresnel microlens array structure imaging film with micro-image array grooves according to claim 1, characterized in that: The thickness of the reflective film layer is 20nm to 200nm.

10. The Fresnel microlens array structure imaging film with micro-image array grooves according to claim 1, characterized in that: The black imaging effect of the composite micro-focusing element array layer comes from the lack of light in the pattern grooves on the surface of the Fresnel micro-lens array, which contrasts with the light reflected by the surrounding lens surfaces into the human eye, so that the human eye observes a black image.

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