A method for preparing an invisible anti-counterfeiting film for electronic device screen recognition

Abstract

The present invention relates to the field of anti-counterfeiting technology, and in particular to a method for preparing an invisible anti-counterfeiting film specially used for screen recognition of electronic devices. The preparation method comprises the following steps: preparing an invisible anti-counterfeiting film layer structure, and the process of preparing the invisible anti-counterfeiting film layer structure comprises imprinting a microstructure grating, and the process of imprinting the microstructure grating comprises the following steps: determining an imprinting space; dividing the imprinting space into a plurality of imprinting subspaces according to the distribution of anti-counterfeiting patterns in the overlapping area of ​​a photosensitive layer and a light-transmitting layer; correspondingly setting a plurality of grating imprinting molds based on the distribution of the plurality of imprinting subspaces; obtaining a temperature control center of the imprinting subspace according to the distribution of anti-counterfeiting patterns in the imprinting subspace; setting a temperature control device on the corresponding grating imprinting mold based on the temperature control center of the imprinting subspace; and controlling the temperature in the imprinting subspace by using the temperature control device on the grating imprinting mold. The present invention can solve the problem of uneven temperature control of the microstructure grating during the imprinting process.

Description

Technical Field

[0001] The invention relates to the field of anti-counterfeiting technology, in particular to a method for preparing an invisible anti-counterfeiting film dedicated to screen recognition of electronic equipment. Background Art

[0002] Micro-optical fantasy technology is an advanced anti-counterfeiting technology based on micro-nano optical structures. It manufactures microstructured gratings on the surface of the material. When light of a specific wavelength (such as blue light) shines on these microstructures, based on the interference, diffraction and scattering effects of light, a colorful visual effect will be formed on the surface of the material.

[0003] With the widespread application of electronic devices in the field of security and anti-counterfeiting, invisible anti-counterfeiting technology dedicated to screen recognition has gradually become an important means of ensuring information security. Especially in devices such as smartphones, the application of anti-counterfeiting films can effectively prevent the emergence of counterfeit and inferior products and ensure that users operate in a safe environment. Such films usually remain transparent under normal light, but after being irradiated with a specific light source (such as blue light), specific anti-counterfeiting patterns can be revealed, thereby verifying the authenticity of the device or document.

[0004] In the manufacturing process of anti-counterfeiting film, the embossing quality of the microstructure grating directly determines the clarity and consistency of the anti-counterfeiting pattern. Since the fluidity of the transparent layer material is highly dependent on temperature, uneven temperature will lead to differences in fluidity in different areas, which will ultimately affect the formation of the microstructure grating. Therefore, how to ensure the temperature uniformity of different areas during the embossing process is an urgent problem to be solved. Summary of the invention

[0005] In view of the deficiencies in the prior art and the needs of practical applications, the present invention provides a method for preparing an invisible anti-counterfeiting film specially used for screen recognition of electronic devices, aiming to solve the problem of uneven temperature control of the microstructure grating of the invisible anti-counterfeiting film during the preparation process.

[0006] The method for preparing the invisible anti-counterfeiting film for electronic device screen recognition provided by the present invention is used to prepare the invisible anti-counterfeiting film, wherein the invisible anti-counterfeiting film comprises an invisible anti-counterfeiting film layer structure formed by stacking a base layer, a photosensitive layer, a light-transmitting layer and a metal layer in sequence, and comprises the following steps:

[0007] The invisible anti-counterfeiting film layer structure is prepared, and the process of preparing the invisible anti-counterfeiting film layer structure includes the following steps:

[0008] Embossed microstructure grating, the microstructure grating is embossed on the surface of the light-transmitting layer away from the photosensitive layer, and the process of embossing the microstructure grating includes the following steps:

[0009] Determine an imprinting space, wherein a projection of the imprinting space in the imprinting direction of the grating imprinting mold coincides with a surface of the light-transmitting layer on a side facing away from the photosensitive layer;

[0010] According to the distribution of the anti-counterfeiting pattern in the overlapping area of ​​the photosensitive layer and the light-transmitting layer, the embossed space is divided into a plurality of embossed subspaces, and the projection of any embossed subspace in the embossing direction covers at least one independent anti-counterfeiting pattern;

[0011] Based on the distribution of the plurality of imprinting subspaces, a plurality of grating imprinting molds are correspondingly arranged, and the projection of any grating imprinting mold in the imprinting direction covers all anti-counterfeiting patterns in the corresponding imprinting subspace;

[0012] According to the distribution of anti-counterfeiting patterns in each imprinting subspace, the temperature control center of the corresponding imprinting subspace is obtained, and based on the temperature control center of each imprinting subspace, a temperature control device is set on the corresponding grating imprinting mold, and the temperature in the corresponding imprinting subspace is controlled by using the temperature control device on each grating imprinting mold.

[0013] Furthermore, the step of obtaining the temperature control center of the corresponding imprinted subspace according to the distribution of the anti-counterfeiting pattern in each imprinted subspace comprises the following steps:

[0014] Based on the projection plane of the imprint subspace in the imprint direction, select any point on the projection plane to construct a coordinate system;

[0015] Based on the coordinate system, obtaining the maximum horizontal coordinate, the minimum horizontal coordinate, the maximum vertical coordinate and the minimum vertical coordinate corresponding to all anti-counterfeiting images in the imprint subspace;

[0016] Based on the maximum abscissa, the minimum abscissa, the maximum ordinate and the minimum ordinate corresponding to all anti-counterfeiting images in the imprinted subspace, the temperature control center of the imprinted subspace is obtained.

[0017] Furthermore, the temperature control device provided on any grating imprinting mold includes a heating component, a temperature measuring component and a temperature control component;

[0018] The method of controlling the temperature in the corresponding imprint subspace by using the temperature control device on each grating imprint mold comprises the following steps:

[0019] The temperature measuring components in each imprinting subspace are used to obtain the real-time temperature of the corresponding temperature control center, and the control device in each imprinting subspace is used to adjust the working state of the corresponding heating component, so that the difference between the real-time temperature of each imprinting subspace and the average real-time temperature at any imprinting moment is minimized.

[0020] Furthermore, the method for preparing the invisible anti-counterfeiting film specially used for electronic device screen recognition is characterized in that any embossing space includes a unique independent anti-counterfeiting pattern.

[0021] Furthermore, any embossing space includes two or more independent anti-counterfeiting patterns.

[0022] Furthermore, the surface of any grating imprinting mold in contact with the light-transmitting layer is covered with periodic raised stripes, any two raised stripes have the same height, any two adjacent raised stripes are parallel, and the spacing ranges from 400 nanometers to 500 nanometers.

[0023] The method for preparing the invisible anti-counterfeiting film for electronic device screen recognition provided by the present invention has the following advantages:

[0024] The present invention divides the imprinting space of the grating mold into a plurality of imprinting subspaces, and respectively determines the temperature control center of each imprinting subspace to arrange a temperature control device; the temperature of each imprinting subspace can be adjusted according to real-time feedback data, thereby ensuring the temperature uniformity of each area, so as to improve the material fluidity of the transparent layer and the accuracy of the microstructure grating, and avoid uneven material flow or excessive flow due to local temperature differences;

[0025] The present invention minimizes the difference between the real-time temperature and the average temperature of each subspace by dynamically adjusting the temperature, reduces the negative impact of the temperature gradient on the formation of the microstructure grating, ensures uniform deformation and flow of materials in all areas during the entire imprinting process, and effectively improves the molding consistency of the microstructure grating and the clarity of the anti-counterfeiting pattern;

[0026] The present invention protects the photosensitive layer from being damaged by excessive temperature by setting an upper temperature limit, and ensures that the transparent layer material has sufficient fluidity by setting a lower temperature limit, thereby providing a dual temperature protection mechanism, which not only effectively prevents the photosensitive layer from failing due to overheating, but also ensures that the transparent layer forms a microstructure grating at a suitable temperature, thereby improving the reliability of the imprinting process;

[0027] The present invention increases the temperature gradient constraint between each imprinting subspace to prevent local overheating or overcooling, further improves the temperature uniformity in the imprinting process, ensures that the temperature difference between each subspace is controlled within the set threshold, thereby ensuring the consistency of the anti-counterfeiting pattern and the overall finished product quality, and reducing errors and unqualified rates in production. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A flow chart of a method for preparing an invisible anti-counterfeiting film for electronic device screen identification provided by an embodiment of the present invention;

[0029] Figure 2 A schematic diagram of the structure of the invisible anti-counterfeiting film provided by an embodiment of the present invention;

[0030] Figure 3 A schematic diagram of the division of the imprinting space provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0031] In the following description, for the purpose of explanation rather than limitation, specific details such as specific system structures and technologies are proposed to facilitate a thorough understanding of the embodiments of the present application.

[0032] In one embodiment, see Figure 1 , Figure 1 A flow chart of a method for preparing an invisible anti-counterfeiting film specially used for electronic device screen identification provided by an embodiment of the present invention.

[0033] In this embodiment, a method for preparing an invisible anti-counterfeiting film specially used for screen recognition of electronic devices is provided for preparing an invisible anti-counterfeiting film, wherein the invisible anti-counterfeiting film comprises an invisible anti-counterfeiting film layer structure formed by stacking a base layer, a photosensitive layer, a light-transmitting layer and a metal layer in sequence, and comprises the following steps: preparing the invisible anti-counterfeiting film layer structure.

[0034] It should be noted that the invisible anti-counterfeiting film of the present invention is Figure 2 As shown, it includes a base layer 1000, a photosensitive layer 2000 arranged on one side of the base layer 1000, a light-transmitting layer 3000 arranged on the side of the photosensitive layer 2000 away from the base layer 1000, a metal layer 4000 arranged on the side of the light-transmitting layer 3000 away from the photosensitive layer 2000, and a colloidal layer 5000 arranged on the side of the metal layer 4000 away from the light-transmitting layer 3000.

[0035] Furthermore, the base layer 1000 is made of a polymer material with high transparency, such as polyethylene terephthalate or polycarbonate, and its thickness ranges from 20 microns to 40 microns; the photosensitive layer 2000 is made of a photosensitive polymer material with sensitive characteristics, especially a photosensitive polymer material sensitive to blue light, and its side away from the base layer 1000 is used to engrave an anti-counterfeiting pattern, and the resolution of the anti-counterfeiting pattern does not exceed 5 microns; the light-transmitting layer 3000 is made of a resin material, and its thickness ranges from 1 micron. to 1.5 microns, and a microstructured grating is embossed on the side away from the photosensitive layer 2000; the metal layer 4000 is made of a metal material with high reflectivity such as aluminum or silver, and its thickness is between 30 nanometers and 40 nanometers; the colloid layer 5000 is made of a self-adhesive or hot-adhesive material, such as a pressure-sensitive adhesive or a heat-sensitive adhesive, and is used to stick the invisible anti-counterfeiting film layer structure formed by stacking the base layer 1000, the photosensitive layer 2000, the light-transmitting layer 3000 and the metal layer 4000 in sequence to the surface of a carrier such as paper.

[0036] In this embodiment, the microstructure grating embossed on the side of the light-transmitting layer 3000 facing away from the photosensitive layer 2000 is a plurality of groups of grating stripes. Different groups of grating stripes are arranged in different areas on the surface of the light-transmitting layer 3000. Any group of grating stripes includes multiple parallel gratings. The spacing between any two adjacent parallel gratings in any group of grating stripes is 400 nanometers to 500 nanometers.

[0037] It is known that the preparation of each functional film layer can be achieved by existing technology, which will not be described in detail here. Further, the process of preparing the invisible anti-counterfeiting film layer structure includes the following steps:

[0038] A microstructure grating is embossed, wherein the microstructure grating is embossed on the surface of the light-transmitting layer facing away from the photosensitive layer.

[0039] To ensure the consistency of the microstructure grating in different areas, such as Figure 1 As shown, the method for preparing the invisible anti-counterfeiting film for electronic device screen recognition provided by the present invention comprises the following steps when imprinting the microstructure grating:

[0040] S01. Determine an imprinting space, wherein a projection of the imprinting space in the imprinting direction of the grating imprinting mold coincides with a surface of the light-transmitting layer on a side facing away from the photosensitive layer.

[0041] Furthermore, the imprinting space described in the present invention refers to the contact area between the grating imprinting mold and the light-transmitting layer, and the microstructure grating imprinting operation is implemented in the contact area.

[0042] S02. Divide the embossing space into a plurality of embossing subspaces according to the distribution of the anti-counterfeiting patterns in the overlapping area between the photosensitive layer and the light-transmitting layer, wherein the projection of any embossing subspace in the embossing direction covers at least one independent anti-counterfeiting pattern.

[0043] See also Figure 3 , Figure 3 A schematic diagram of the division of the imprinting space provided in an embodiment of the present invention.

[0044] like Figure 3 As shown in Figure (a), in order to ensure that the microstructure grating corresponding to each anti-counterfeiting pattern can be accurately embossed, the embossing space is divided into multiple embossing subspaces, and any embossing space includes a unique independent anti-counterfeiting pattern.

[0045] like Figure 3 As shown in Figure (b), in order to improve the overall production efficiency and reduce the manufacturing cost of each pattern, the imprinting space is divided into multiple imprinting subspaces, and any imprinting space includes two or more independent anti-counterfeiting patterns.

[0046] It is understood that the independent anti-counterfeiting pattern described in the present invention refers to an anti-counterfeiting feature designed on the photosensitive layer of the invisible anti-counterfeiting film layer structure and capable of being independently identified or verified. Further, any two independent anti-counterfeiting patterns can be the same pattern or different patterns.

[0047] S03. Based on the distribution of the plurality of imprinting subspaces, a plurality of grating imprinting molds are correspondingly arranged, and the projection of any grating imprinting mold in the imprinting direction covers all anti-counterfeiting patterns in the corresponding imprinting subspace.

[0048] It can be understood that the grating imprinting mold described in the present invention is used to transfer a pre-designed microstructure grating pattern to the surface of the light-transmitting layer away from the photosensitive layer by imprinting; it is usually made of hard materials (such as metals, ceramics or high-hardness polymers), and a specific grating pattern is etched on the surface by high-precision etching techniques such as laser etching, electron beam etching or chemical etching.

[0049] In this embodiment, in order to realize the blue light display anti-counterfeiting pattern on the screen of the electronic device, the surface of any grating imprinting mold in contact with the light-transmitting layer is covered with periodic raised stripes, any two raised stripes have the same height, any two adjacent raised stripes are parallel, and the spacing ranges from 400 nanometers to 500 nanometers.

[0050] S04. Obtaining the temperature control center of the corresponding imprinted subspace according to the distribution of the anti-counterfeiting pattern in each imprinted subspace.

[0051] Furthermore, the temperature control center proposed in the present invention refers to an ideal temperature control point set for each imprinting subspace during the imprinting process.

[0052] It can be understood that the temperature control center proposed in the present invention is the key to temperature monitoring and regulation. The temperature setting of the temperature control center needs to ensure that the transparent layer can effectively deform and flow during printing, thereby forming the required microstructure grating, while the photosensitive layer maintains its chemical properties and photosensitivity without being affected by temperature.

[0053] In one or some other embodiments, in order to ensure the consistency of the microstructure gratings corresponding to all independent anti-counterfeiting images in each imprinted subspace, for the temperature control center of each imprinted subspace, the step S04 of obtaining the temperature control center of the corresponding imprinted subspace according to the distribution of the anti-counterfeiting patterns in each imprinted subspace includes the following steps:

[0054] S041. Based on the projection plane of the imprint subspace in the imprint direction, select any point on the projection plane to construct a coordinate system.

[0055] S042. Based on the coordinate system, obtain the maximum horizontal coordinate, the minimum horizontal coordinate, the maximum vertical coordinate and the minimum vertical coordinate corresponding to all anti-counterfeiting images in the imprint subspace.

[0056] S043. Obtaining a temperature control center of the imprinted subspace based on the maximum abscissa, the minimum abscissa, the maximum ordinate, and the minimum ordinate corresponding to all anti-counterfeiting images in the imprinted subspace.

[0057] Furthermore, the horizontal coordinate x of the temperature control center satisfies the following calculation model: Where x represents the horizontal coordinate of the temperature control center in the imprint subspace, x max represents the maximum horizontal coordinate of the anti-counterfeiting image in the imprinted subspace, x min Represents the minimum horizontal coordinate of the anti-counterfeiting image in the imprinted subspace.

[0058] Furthermore, the ordinate y of the temperature control center satisfies the following calculation model: Where y represents the vertical coordinate of the temperature control center in the imprint subspace, y max Represents the maximum ordinate of the anti-counterfeiting image in the imprinted subspace, y min Represents the minimum vertical coordinate of the anti-counterfeiting image in the embossed subspace.

[0059] S05 , respectively setting a temperature control device on the corresponding grating imprinting mold based on the temperature control center of each imprinting subspace.

[0060] Furthermore, the temperature control device arranged on any grating imprinting mold includes a heating component, a temperature measuring component and a temperature control component, wherein the heating component is used to heat the surface of the corresponding grating imprinting mold, the temperature measuring component is used to monitor the surface temperature of the corresponding grating imprinting mold, the temperature control component is connected to the signal of the heated component, and the temperature control component is used to control the working state of the heating component.

[0061] In this embodiment, the heating component in the temperature control device provided by the present invention corresponds to the temperature control center of the corresponding imprinted subspace; further, the heating component based on the temperature control center heats the surface of the light-transmitting layer corresponding to the imprinted subspace, ensuring that the heat of the heating component can be evenly distributed in the temperature control center and its surrounding area, thereby avoiding uneven material flow caused by temperature gradients and ensuring the formation quality and consistency of the microstructure grating.

[0062] S06, using the temperature control device on each grating imprinting mold to control the temperature in the corresponding imprinting subspace.

[0063] Furthermore, in order to ensure the consistency of the microstructure gratings in different areas on the surface of the light-transmitting layer corresponding to the imprinting space, the temperature in the corresponding imprinting subspace is controlled by using the temperature control device on each grating imprinting mold in step S06, including the following steps:

[0064] S061. Use the temperature measuring components in each imprinting subspace to obtain the real-time temperature of the corresponding temperature control center, and use the control device in each imprinting subspace to adjust the working state of the corresponding heating component, so that the difference between the real-time temperature of each imprinting subspace and the average real-time temperature at any imprinting moment is minimized.

[0065] Specifically, at an imprinting time t, the objective function of temperature control in the imprinting space satisfies the following model: Where n represents the total number of imprinted subspaces, It indicates that the temperature measurement component in the i-th imprint subspace obtains the real-time temperature of the corresponding temperature control center at the imprint time t. Represents the average real-time temperature of each imprinted subspace at the imprinting time t.

[0066] It should be noted that in order to avoid the influence of excessively high temperature on the photosensitive layer during the imprinting process, and to avoid the poor imprinting effect of the microstructure grating due to insufficient fluidity of the light-transmitting layer material caused by too low temperature, the above objective function also includes the following constraints:

[0067] The first constraint is: Among them, T max Indicates the maximum tolerable temperature of the photosensitive layer.

[0068] Second constraint: Among them, T min It indicates the lowest temperature at which the transparent layer can maintain sufficient fluidity to form a microstructured grating during the imprinting process.

[0069] To further ensure uniformity during the imprinting process and avoid local overheating or overcooling, in one or more other embodiments, the objective function further includes the following constraints:

[0070] The third constraint is: Where, ΔT H represents a preset temperature gradient threshold; it can be understood that the preset temperature gradient threshold ΔT H Usually set according to material properties and process requirements.

[0071] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0072] It should be noted that the above embodiments can be freely combined as needed. The above is only a preferred implementation of the present invention; it should be noted that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a stealth anti-counterfeiting film for electronic device screen recognition, the method being used to prepare a stealth anti-counterfeiting film, the stealth anti-counterfeiting film comprising a stealth anti-counterfeiting film layer structure formed by stacking a base layer, a photosensitive layer, a light-transmitting layer and a metal layer in sequence, characterized in that: The steps include: The invisible anti-counterfeiting film layer structure is prepared, and the process of preparing the invisible anti-counterfeiting film layer structure includes the following steps: Embossed microstructure grating, the microstructure grating is embossed on the surface of the light-transmitting layer away from the photosensitive layer, and the process of embossing the microstructure grating includes the following steps: Determine an imprinting space, wherein a projection of the imprinting space in the imprinting direction of the grating imprinting mold coincides with a surface of the light-transmitting layer on a side facing away from the photosensitive layer; According to the distribution of the anti-counterfeiting pattern in the overlapping area of ​​the photosensitive layer and the light-transmitting layer, the embossed space is divided into a plurality of embossed subspaces, and the projection of any embossed subspace in the embossing direction covers at least one independent anti-counterfeiting pattern; Based on the distribution of the plurality of imprinting subspaces, a plurality of grating imprinting molds are correspondingly arranged, and the projection of any grating imprinting mold in the imprinting direction covers all anti-counterfeiting patterns in the corresponding imprinting subspace; According to the distribution of anti-counterfeiting patterns in each imprinting subspace, the temperature control center of the corresponding imprinting subspace is obtained, and based on the temperature control center of each imprinting subspace, a temperature control device is set on the corresponding grating imprinting mold, and the temperature in the corresponding imprinting subspace is controlled by using the temperature control device on each grating imprinting mold.

2. The method for preparing the invisible anti-counterfeiting film for electronic device screen recognition according to claim 1, characterized in that: The method of obtaining the temperature control center of the corresponding embossed subspace according to the distribution of the anti-counterfeiting pattern in each embossed subspace comprises the following steps: Based on the projection plane of the imprint subspace in the imprint direction, any point is selected from the projection plane to construct a coordinate system.

3. The method for preparing the invisible anti-counterfeiting film for electronic device screen recognition according to claim 2, characterized in that: The method of obtaining the temperature control center of the corresponding embossed subspace according to the distribution of the anti-counterfeiting pattern in each embossed subspace comprises the following steps: Based on the coordinate system, the maximum horizontal coordinate, the minimum horizontal coordinate, the maximum vertical coordinate and the minimum vertical coordinate corresponding to all anti-counterfeiting images in the imprint subspace are obtained.

4. The method for preparing the invisible anti-counterfeiting film for electronic device screen recognition according to claim 3, characterized in that: The method of obtaining the temperature control center of the corresponding embossed subspace according to the distribution of the anti-counterfeiting pattern in each embossed subspace comprises the following steps: Based on the maximum abscissa, the minimum abscissa, the maximum ordinate and the minimum ordinate corresponding to all anti-counterfeiting images in the imprinted subspace, the temperature control center of the imprinted subspace is obtained.

5. The method for preparing the invisible anti-counterfeiting film for electronic device screen recognition according to claim 1, characterized in that: The temperature control device provided on any grating imprinting mold comprises a heating component, a temperature measuring component and a temperature control component; The method of controlling the temperature in the corresponding imprint subspace by using the temperature control device on each grating imprint mold comprises the following steps: The temperature measuring components in each imprinting subspace are used to obtain the real-time temperature of the corresponding temperature control center, and the control device in each imprinting subspace is used to adjust the working state of the corresponding heating component, so that the difference between the real-time temperature of each imprinting subspace and the average real-time temperature at any imprinting moment is minimized.

6. The method for preparing the invisible anti-counterfeiting film for electronic device screen recognition according to any one of claims 1 to 5, characterized in that: Any embossed space includes only one independent anti-counterfeiting pattern.

7. The method for preparing the invisible anti-counterfeiting film for electronic device screen recognition according to any one of claims 1 to 5, characterized in that: Any embossing space includes two or more independent anti-counterfeiting patterns.

8. The method for preparing the invisible anti-counterfeiting film for electronic device screen recognition according to any one of claims 1 to 7, characterized in that: The surface of any grating imprinting mold in contact with the light-transmitting layer is covered with periodic raised stripes, any two raised stripes have the same height, any two adjacent raised stripes are parallel, and the spacing ranges from 400 nanometers to 500 nanometers.

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