A hot stamping film anti-counterfeiting method with band-pass frequency selection set encoding

Abstract

This invention provides a hot stamping film anti-counterfeiting method using bandpass frequency selection set encoding, comprising: arbitrarily selecting N frequencies; designing a set of resonant units corresponding to the frequencies; selecting an anti-counterfeiting area on the cold stamping film and determining the frequency corresponding to the unit anti-counterfeiting block; preparing a set of resonant units corresponding to each unit anti-counterfeiting block area on the cold stamping film; and then transferring the cold stamping film to the product surface. During anti-counterfeiting detection, for the anti-counterfeiting area, the selected N frequencies are traversed to detect whether the anti-counterfeiting area can conduct all frequencies. If it can, the product is genuine; otherwise, the product is counterfeit. This invention utilizes the advantage of frequency-selective surfaces having good frequency selectivity. By designing a frequency-selective surface structure corresponding to the frequency and preparing a surface structure corresponding to the corresponding code on the cold stamping film based on the encoding combination, advanced anti-counterfeiting functions can be achieved, with advantages such as high anti-counterfeiting performance, good adaptability, and low cost.

Description

Technical Field

[0001] This invention belongs to the field of anti-counterfeiting film technology, specifically relating to a hot stamping film anti-counterfeiting method using bandpass frequency set encoding. Background Technology

[0002] Current anti-counterfeiting technologies mainly include laser holographic marking, hidden image anti-counterfeiting, barcodes, QR codes, and chemical ink printing. These anti-counterfeiting methods are widely used because their physical principles are simple and easy to understand, they can be industrially produced, and their production costs are low. However, with the popularization and public disclosure of these technologies, their anti-counterfeiting functions have significantly decreased, making it difficult to achieve high-level anti-counterfeiting. Therefore, there is an urgent need to find an anti-counterfeiting technology with higher production technical barriers and greater security and reliability.

[0003] Chinese invention patent application No. 202210334315.4 discloses a near-field and far-field dual-channel image display method based on metasurface materials. This method combines metasurface microstructures with QR code patterns to achieve image display for anti-counterfeiting purposes. Chinese invention patent application No. 202210478851.1 discloses a face recognition method for anti-counterfeiting authentication scenarios based on photo verification. This method creates special anti-counterfeiting textures or patterns, takes a photo during querying, analyzes it, uploads it, and performs online comparison to achieve anti-counterfeiting. These methods are easily counterfeited in large quantities and at low cost through high-precision copying, reducing the security and reliability of anti-counterfeiting codes. Furthermore, they often require pre-storing anti-counterfeiting texture or pattern information on a server, necessitating significant storage space and relatively time-consuming verification.

[0004] In addition, typical photochromic anti-counterfeiting films (CN114685832A) usually include a base layer, a hidden layer, and a top coating layer. Different colors are achieved by adjusting the ratio of fluorescent dyes in the hidden layer. Visually, it appears as one color changing into another. The effect is relatively simple, the reliability is not high, and it cannot meet the requirements of higher-level anti-counterfeiting. Summary of the Invention

[0005] To address the shortcomings of the prior art, this invention provides a hot stamping film anti-counterfeiting method using bandpass frequency set encoding.

[0006] This invention is achieved through the following technical solution:

[0007] A hot stamping film anti-counterfeiting method with bandpass frequency set coding includes the following steps:

[0008] (1) Within the frequency range of 100kHz to 1MHz, N different frequencies can be arbitrarily selected;

[0009] (2) Design the set of resonant units corresponding to each frequency selected in step (1), which includes several resonant units with the same shape arranged periodically.

[0010] (3) Select an area on the cold foil as the anti-counterfeiting area, divide the anti-counterfeiting area into N unit anti-counterfeiting blocks, and assign each unit anti-counterfeiting block to a frequency in step (1).

[0011] (4) Based on the frequency corresponding to each unit anti-counterfeiting block in the anti-counterfeiting area, and according to the characteristics of the resonant unit set corresponding to the frequency designed in step (2), prepare the resonant unit set corresponding to each unit anti-counterfeiting block area on the cold foil.

[0012] (5) Transfer the cold foil with anti-counterfeiting area to the product surface. The substrate of the product must not be metal and the thickness must not exceed 10mm.

[0013] (6) During anti-counterfeiting detection, for the anti-counterfeiting area, traverse the N frequencies selected in step (1) and check whether the anti-counterfeiting area can conduct all frequencies. If it can, the product is genuine; otherwise, the product is fake.

[0014] The present invention has the following beneficial effects:

[0015] 1. The hot stamping film anti-counterfeiting method of bandpass frequency selection set coding described in this invention utilizes the advantage of frequency selective surface to good frequency selectivity. By designing a frequency selective surface structure corresponding to the frequency, and preparing a surface structure corresponding to the corresponding code on the cold stamping film based on the code combination, advanced anti-counterfeiting function can be achieved. It has the advantages of high anti-counterfeiting performance, good adaptability, and low cost.

[0016] 2. The hot stamping film anti-counterfeiting method of bandpass frequency selection set coding described in this invention has many design parameters, including micro-unit structure, size, arrangement, material, etc., and the coding form is diverse. It is difficult to counterfeit when the original design parameters are unknown, and the anti-counterfeiting method is reliable.

[0017] 3. The flexible cold foil with anti-counterfeiting mark prepared by the hot foil stamping anti-counterfeiting method of bandpass frequency set coding described in this invention has the advantages of being convenient, flexible, adaptable and low cost. It has a disposable feature and cannot be restored once damaged, thus having good self-protection.

[0018] 4. The hot stamping film anti-counterfeiting method of bandpass frequency set encoding described in this invention, when performing anti-counterfeiting detection, only needs to traverse the selected N frequencies for the anti-counterfeiting area to detect whether the anti-counterfeiting area can conduct all frequencies. The detection method is simple, easy to implement, and efficient, and has great commercial promotion value. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of an open rectangular ring resonator unit;

[0020] Figure 2This is a schematic diagram of an open circular ring resonator unit. Detailed Implementation

[0021] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings, but this description is not intended to limit the present invention.

[0022] Frequency Selective Surface (FSS) is a novel artificially designed periodic structure array that can achieve passband full transmission or bandstop phenomenon of total reflection of incident electromagnetic waves by changing the unit size and arrangement rules. It has the advantages of high frequency selectivity, simple device structure and small size, and good angular stability, and is therefore widely used in the design and development of communication devices.

[0023] This invention provides a hot stamping film anti-counterfeiting method with bandpass frequency set encoding, specifically including the following steps:

[0024] (1) Within the frequency range of 100kHz to 1MHz, N different frequencies can be arbitrarily selected. Theoretically, the frequency range can also be chosen arbitrarily, but the higher the frequency (such as GHz, THz), the more expensive the detection equipment will be. Therefore, lower frequencies are preferred.

[0025] (2) Design the set of resonant units corresponding to each frequency selected in step (1). The set of resonant units includes several resonant units arranged periodically with the same shape. The features of the set of resonant units include the shape (e.g., open circular ring, open rectangular ring, etc.) and size parameters of the resonant units, as well as the periodic arrangement method (e.g., square array, regular polygon array, etc.) and arrangement spacing parameters of the resonant units.

[0026] Figure 1 The diagram shows an open rectangular ring resonator unit. The desired FSS frequency can be achieved by changing the dimensions g, w, and l, as well as the periodic arrangement parameters. For example, when g = 0.4 mm, w = 0.4 mm, l = 5 mm, and the periodic arrangement is a square array with a spacing of 1 mm, the FSS frequency is 200 kHz. When g = 1 mm, w = 0.8 mm, l = 8 mm, and the periodic arrangement is a square array with a spacing of 1.5 mm, the FSS frequency is 100 kHz.

[0027] Figure 2The diagram shows an open circular ring resonator unit. The desired FSS frequency can be achieved by changing the dimensions r1, r2, and g, as well as the center distance p. For example, when g = 0.4 mm, r1 = 1.4 mm, and r2 = 1.8 mm, the FSS frequency is 220 kHz when the periodic arrangement is a square array and the center distance p is 5 mm. Similarly, when g = 0.25 mm, r1 = 1 mm, and r2 = 1.2 mm, the FSS frequency is 290 kHz when the periodic arrangement is a square array and the center distance p is 3 mm.

[0028] (3) Select an area on the cold foil as the anti-counterfeiting area, divide the anti-counterfeiting area into N unit anti-counterfeiting blocks, and assign each unit anti-counterfeiting block to a frequency in step (1).

[0029] (4) Based on the frequency corresponding to each unit anti-counterfeiting block in the anti-counterfeiting area; according to the characteristics of the resonant unit set corresponding to the frequency designed in step (2), prepare the resonant unit set corresponding to each unit anti-counterfeiting block area on the cold foil.

[0030] The specific preparation method is as follows: First, a metal film is deposited on the cold hot stamping film, and then the above-mentioned resonant unit set is prepared on the metal film by laser etching technology; Alternatively, a mask of the resonant unit set can be prepared in advance, and then the metal resonant unit set can be directly deposited on the cold hot stamping film through the mask.

[0031] (5) Transfer the cold foil with anti-counterfeiting area to the product surface. The substrate of the product cannot be metal. Its material can include PVC, acrylic, cardboard, wood, cloth, etc., and its thickness cannot exceed 10mm.

[0032] (6) During anti-counterfeiting detection, for the anti-counterfeiting area, traverse the N frequencies selected in step (1) and check whether the anti-counterfeiting area can conduct all frequencies. If it can, the product is genuine; otherwise, the product is fake.

[0033] When comparing frequencies one by one, if a selected frequency is found to be inconsistent, the comparison can be stopped and the product can be directly judged as fake.

[0034] To reduce the workload of anti-counterfeiting detection, one or more of the 1 to N unit anti-counterfeiting blocks can be randomly selected for detection. If the frequencies are found to be different, the comparison can be stopped and the product can be directly judged as fake.

[0035] It will be apparent to those skilled in the art that the present invention can be modified in various ways, and such modifications are not considered to depart from the scope of the invention. All such modifications that are obvious to those skilled in the art are included within the scope of the claims.

Claims

1. A hot stamping film anti-counterfeiting method using bandpass frequency set coding, characterized in that, Includes the following steps: (1) Within the frequency range of 100kHz to 1MHz, N different frequencies can be arbitrarily selected; (2) Design the set of resonant units corresponding to each frequency selected in step (1), which includes several resonant units with the same shape arranged periodically. (3) Select an area on the cold foil as the anti-counterfeiting area, divide the anti-counterfeiting area into N unit anti-counterfeiting blocks, and assign each unit anti-counterfeiting block to a frequency in step (1). (4) Based on the frequency corresponding to each unit anti-counterfeiting block in the anti-counterfeiting area, and according to the characteristics of the resonant unit set corresponding to the frequency designed in step (2), prepare the resonant unit set corresponding to each unit anti-counterfeiting block area on the cold foil. (5) Transfer the cold foil with anti-counterfeiting area to the product surface. The substrate of the product must not be metal and the thickness must not exceed 10mm. (6) During anti-counterfeiting detection, for the anti-counterfeiting area, traverse the N frequencies selected in step (1) and check whether the anti-counterfeiting area can conduct all frequencies. If it can, the product is genuine; otherwise, the product is fake.

2. The hot stamping film anti-counterfeiting method with bandpass frequency set coding according to claim 1, characterized in that, The features of the resonant unit set in step (2) include the shape and size parameters of the resonant units, as well as the periodic arrangement and spacing of the resonant units.

3. The hot stamping film anti-counterfeiting method with bandpass frequency set coding according to claim 1, characterized in that, The specific preparation method for preparing the corresponding resonant unit set for each unit anti-counterfeiting block area on the cold hot stamping film in step (4) is as follows: First, a metal film is deposited on the cold hot stamping film, and then the above-mentioned resonant unit set is prepared on the metal film by laser etching technology.

4. The hot stamping film anti-counterfeiting method with bandpass frequency set coding according to claim 1, characterized in that, The specific preparation method for preparing the corresponding resonant unit set for each unit anti-counterfeiting block area on the cold hot stamping film in step (4) is as follows: prepare a mask for the resonant unit set in advance, and then deposit the metal resonant unit set directly on the cold hot stamping film through the mask.

5. The hot stamping film anti-counterfeiting method with bandpass frequency set coding according to claim 1, characterized in that, The material of the product in step (5) is PVC, acrylic, cardboard, wood or cloth.

6. The hot stamping film anti-counterfeiting method with bandpass frequency set coding according to claim 1, characterized in that, In step (6), when comparing frequencies, if a frequency is found to be out of sync, the comparison will not continue and the product will be judged as fake.

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