A method for anti-counterfeiting of mobile phone screens using the principle of moiré fringes

Abstract

The present invention discloses a method for realizing anti-counterfeiting of mobile phone screens by utilizing the moiré fringe principle. The method comprises the following steps: first, inputting a basic function through software to obtain a corresponding function image; second, modifying and deforming the basic function parameters and the stripe colors to generate rich colored stripes; third, superimposing two or more groups of colored stripes to generate a new color moiré fringe pattern in the superimposed portion; fourth, calculating an equation for generating moiré fringe by superimposing curved grids; fifth, printing patterns of different color regions on transparent paper respectively, superimposing them on each other to obtain a colored pattern, regarding the mobile phone screen as a grid, superimposing the colored pattern and the grid, different moiré fringe patterns will appear in different color regions, and printing the resulting pattern as the correct superimposed pattern in the lower right corner of the image; and sixth, taking a photo using a picture of the grid and a bottom grid, superimposing the moiré fringes in the bottom grid picture with the grid of the mobile phone screen to generate a moiré fringe pattern, and comparing the generated moiré fringe pattern with the correct moiré fringe color pattern.

Description

Technical Field

[0001] The invention belongs to the field of optical technology, and in particular is a method for realizing anti-counterfeiting of mobile phone screens by utilizing the moiré fringe principle. Background Art

[0002] Moire fringes are an optical phenomenon first discovered by the 18th-century French researcher Monsieur More. They are the visual result of interference between two lines or objects at a constant angle and frequency. When the human eye cannot distinguish the two lines or objects, only the interference pattern is visible. This optical phenomenon is called moiré fringes. Moiré fringes appear when there is a certain spatial frequency difference between two sets of grids.

[0003] Currently, the most common anti-counterfeiting methods include digital security, electronic code security, laser security, QR code security, WeChat query security, and digital watermark security. Electronic code security is the most commonly used and most common method, such as website query and WeChat query. This anti-counterfeiting method mostly requires an internet connection and is somewhat complex, which can limit its use in areas without an internet connection. Summary of the Invention

[0004] To address this issue, the present invention proposes a method for anti-counterfeiting mobile phone screens using the principle of moiré fringes. This technology uses a mobile phone to take a photo with a base grid made by superimposing grids of different colors and spacing. This creates different moiré patterns in different color regions, which are then compared with the correct moiré pattern to achieve anti-counterfeiting. This method is simple and easy to use, and overcomes network limitations.

[0005] The present invention is achieved through the following technical solutions:

[0006] A method for anti-counterfeiting a mobile phone screen by using the moiré fringe principle comprises the following steps:

[0007] Step 1: Input the basic function through MATLAB software and obtain the grid corresponding to the function stripes;

[0008] Step 2: Modify and deform the parameters of the basic function and the color of the stripes to generate richer colored stripes;

[0009] Step 3: Overlay two or more sets of color stripes to generate a new color moiré pattern in the overlapped portion, while the unoverlapped portion remains stripes of the original color.

[0010] Step 4: Use the formula to calculate the equation for the moiré fringes produced by the superposition of several curved gratings;

[0011] Step 5: Print the patterns with different color areas onto transparent images of the same size and overlay them to form a color pattern. Treat the phone screen as a grid and overlay the color pattern with the grid on the phone screen. During the overlay, different moiré patterns will appear in different color areas. The resulting pattern is used as the correct overlay pattern and printed in the lower right corner of the image for comparison during anti-counterfeiting.

[0012] Step 6. Take a photo using the grid and bottom grid images of the mobile phone screen, so that the moiré fringes in the bottom grid image are superimposed on the grid of the mobile phone screen to produce a moiré fringe pattern. Compare the generated moiré fringe pattern with the correct moiré fringe color pattern printed in the lower right corner of the image. If the two are consistent, it is judged to be true, otherwise it is false.

[0013] Furthermore, the basic functions in step one include sine function and cosine function.

[0014] Furthermore, when two sets of color stripes are superimposed, the equation for the moiré stripes generated by the superposition of two curved stripes is:

[0015] Furthermore, the specific method for calculating the moiré fringe equation generated by the superposition of two curved gratings is as follows:

[0016] Use two curved grids to superimpose each other. The equations of the two curved grids are

[0017] y1=f(x)+md

[0018] y2=g(x)+md′;

[0019] Transforming the equations of the two curved grids, we get the following:

[0020]

[0021]

[0022] When y1=y2, the equation of the generated moiré fringes can be obtained by subtracting the above two equations.

[0023] The beneficial effects of the present invention are:

[0024] 1. The present invention uses simple grid superposition to achieve the purpose of anti-counterfeiting. When used in combination with a mobile phone, it is easy to operate and convenient to compare, and it also meets the anti-counterfeiting effect.

[0025] 2. This invention combines two or more grids to create a bottom grid, which is then superimposed on the grid of the phone screen to produce moiré patterns. Using the theoretical formula for moiré patterns generated by superimposing curved grids, the precise function that generates moiré patterns can be calculated. However, using only the moiré function, it is difficult to deduce variations and combinations of the underlying function, thus increasing the difficulty of cracking and achieving the desired anti-counterfeiting effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The square grille of the mobile phone screen;

[0027] Figure 2 is the bottom grid;

[0028] Figure 3 To print the correct image to the bottom grid after the lower right corner;

[0029] Figure 4 The colorful pattern formed by the superposition of the mobile phone screen and the bottom grille;

[0030] Reference numerals: 1. red grid of the function y1=atan(x), 2. blue grid of the function y2=acot(x), 3. purple moiré fringes formed by superposition, 4. correct color result pattern. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present invention are described clearly and completely below with reference to the accompanying drawings.

[0032] Example 1

[0033] As shown in the accompanying drawings, a method for implementing anti-counterfeiting on mobile phone screens using the Moire fringe principle includes the following steps:

[0034] (1) Inputting basic functions through MATLAB software to obtain corresponding function graphs, wherein the basic functions include sine function and cosine function;

[0035] (2) By modifying and deforming the parameters of the basic function and the color of the stripes, more colorful stripes can be generated;

[0036] (3) Superimpose two or more groups of color stripes to produce a new color moiré pattern in the superimposed part, while the unsuperimposed part remains the stripes of the original color. For example, take two groups and superimpose the red stripes and the blue stripes. Figure 2 The overlapping area of ​​the red and blue stripes is a purple moiré pattern, and the non-overlapping area is the original red and blue stripes. Figure 2 as a bottom grid;

[0037] (4) Two curved grids are superimposed, and the equations of the curved grids are

[0038] y1=acttan(x)+md (1)

[0039] y2=actcot(x)+nd′ (2)

[0040] Transforming the equations of the two curved grids, we get the following:

[0041]

[0042]

[0043] When y1=y2, subtract the above two equations, (3)-(4) to obtain the equation of the generated moiré fringes as follows:

[0044]

[0045] (5) Figure 1 In the process, the mobile phone screen is regarded as a grid. Patterns with different color areas are printed separately on transparent images of the same size. The superimposed patterns are obtained by superimposing each other. The color patterns are superimposed on the grid of the mobile phone screen. Different moiré patterns will appear in different color areas during the superposition. The resulting pattern is used as the correct superimposed pattern and printed at the lower right corner of the bottom grid (see Figure 3 ), used for comparison during anti-counterfeiting;

[0046] (6) Take a photo using the grid and bottom grid of the mobile phone screen, so that the moiré fringes in the photo are superimposed on the grid of the mobile phone screen to produce a moiré pattern (see Figure 4 ), compare the generated moiré fringe pattern with the correct moiré fringe color pattern printed in the lower right corner of the image. If the two are consistent, it is judged to be true, otherwise it is false.

[0047] The present invention uses a theoretical formula for moiré patterns generated by superimposing curved gratings to calculate the exact function that generates moiré patterns. However, relying solely on the moiré function makes it difficult to deduce variations and combinations of the underlying function, thus increasing the difficulty of cracking and achieving the purpose of anti-counterfeiting.

[0048] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which shall fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for anti-counterfeiting mobile phone screens using the Moire fringe principle, characterized by: The following steps are involved: Step 1: Input the basic function through MATLAB software and obtain the grid corresponding to the function stripes; Step 2: Modify and deform the parameters of the basic function and the color of the stripes to generate richer colored stripes; Step 3: Overlay two or more sets of color stripes to generate a new color moiré pattern in the overlapped portion, while the unoverlapped portion remains stripes of the original color. Step 4: Use the formula to calculate the equation for the moiré fringes produced by the superposition of several curved gratings; Step 5: Print the patterns of the curved grids of different colors onto transparent images of the same size, and superimpose them to obtain a colored pattern. Treat the mobile phone screen as a grid, and superimpose the colored pattern and the grid on the mobile phone screen. The resulting pattern is used as the correct superimposed pattern and printed in the lower right corner of the image for comparison during anti-counterfeiting. Step 6. Take a photo using the grid and bottom grid images of the mobile phone screen, so that the moiré fringes in the bottom grid image are superimposed on the grid of the mobile phone screen to produce a moiré fringe pattern. Compare the generated moiré fringe pattern with the correct moiré fringe color pattern printed in the lower right corner of the image. If the two are consistent, it is judged to be true, otherwise it is false.

2. The method for anti-counterfeiting mobile phone screens using the moiré fringe principle according to claim 1, characterized in that: The basic functions in step 1 include sine function and cosine function.

3. The method for anti-counterfeiting mobile phone screens using the moiré fringe principle according to claim 1, characterized in that: When two sets of color stripes are superimposed, there are two curved gratings in step 4. The equation for the moiré stripes generated by the superposition of the two curved gratings is:

4. The method for anti-counterfeiting mobile phone screens using the moiré fringe principle according to claim 3, characterized in that: The specific method for calculating the moiré fringe equation generated by the superposition of two curved gratings is as follows: Use two curved grids to superimpose each other. The equations of the two curved grids are y1=f(x)+md y2=g(x)+md′; Transforming the equations of the two curved grids, we get the following: When y1=y2, the equation of the generated moiré fringes can be obtained by subtracting the above two equations.

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