CN202142123U - A counterfeit device for banknotes or bills - Google Patents

Abstract

The utility model belongs to the technical field of optical applications, and discloses a counterfeit device for banknotes or bills, comprising: an infrared transmission light source and/or an infrared reflection light source; a transmission light control switch connected with the infrared transmission light source and/or connected to the The reflective light control switch connected to the infrared reflective light source; the image sensor; the light of the infrared reflective light source transmitted by the sample to be identified or the light of the infrared reflective light source reflected by the sample to be identified is imaged on the image sensor. a lens; a computer connected with the image sensor; a display connected with the computer. The utility model performs infrared imaging on the sample to be identified by infrared reflection and transmission light sources and an image sensor to generate anti-counterfeit features that cannot be seen under visible light, and combined with a display, it can observe the difference between real and fake banknotes in real time. The purpose of anti-counterfeiting is achieved by this means, and the reliability of counterfeiting is improved to a certain extent.

Description

A counterfeit device for banknotes or bills

technical field

The utility model relates to the field of optical application technology, in particular to a counterfeit identification device based on infrared imaging technology, which is suitable for counterfeit identification of banknotes or bills.

Background technique

For example, the identification of counterfeit items such as banknotes and bills is to distinguish the true from the false by detecting the inherent characteristics of the sample. After the traditional counterfeiting technology has experienced the first generation fluorescent counterfeiting technology (1900), the second generation magnetic ink counterfeiting technology (1996), and the third generation security line detection technology (2002), its authenticity of counterfeiting is increasing. face serious challenges.

Taking RMB as an example, the degree of imitation of various counterfeit banknotes is getting higher and higher. In particular, most of the artificial anti-counterfeiting marks have been mastered by counterfeiters. To judge the authenticity of banknotes, the reliability is bound to be greatly reduced.

Utility model content

The technical problem to be solved by the utility model is to provide a counterfeit identification device for banknotes or bills, aiming at realizing counterfeit identification means with higher reliability to realize counterfeit identification of banknotes, bills and the like.

In order to solve the above-mentioned technical problems, the technical solution of the present invention is to provide a counterfeit device for banknotes or bills, including:

Infrared transmitted light source and/or infrared reflected light source;

A transmitted light control switch connected to the infrared transmission light source and/or a reflected light control switch connected to the infrared reflection light source;

Image Sensor;

An optical lens that images the light of the infrared transmission light source transmitted by the sample to be identified or the light of the infrared reflection light source reflected by the sample to be identified on the image sensor;

a computer connected to the image sensor;

A monitor connected to said computer.

Further, the infrared transmission light source and/or infrared reflection light source, the image sensor, and the optical lens are placed in a dark box.

Further, a stage is provided at the bottom of the dark box, the infrared transmission light source is installed on the lower part of the stage, and a holding plate for holding the sample to be identified is arranged on the stage.

Further, the clamping plate is an acrylic plate.

Further, the infrared reflective light source is an infrared LED array light emitting unit.

Further, the infrared transmission light source includes a light guide plate printed with diffuse dots, an infrared light source arranged on the side of the light guide plate, and a sticker on the upper surface of the light guide plate corresponding to the position of the infrared light source The upper total reflection film, the upper surface of the light guide plate is pasted with a diffusion film at least at positions other than the upper total reflection film; the lower surface of the light guide plate is pasted with a lower total reflection film.

Further, the upper total reflection film is an aluminum film, and at least the part of the lower total reflection film corresponding to the infrared light source is an aluminum film.

Further, on the light guide plate, the size of the diffused dots close to the infrared light source is smaller than the size of the diffused dots away from the infrared light source.

Further, on the light guide plate, the density of the diffused dots close to the infrared light source is smaller than the density of the diffused dots far away from the infrared light source.

Further, the infrared light source includes several infrared LED lamps; several recessed parts are provided on the side of the light guide plate; and the several infrared LED lamps are arranged in the several recessed parts one by one.

The utility model considers that banknotes form a complete color pattern under white light, but there are many unique phenomena in banknote imaging under infrared light, such as concave-convex patterns, incomplete patterns with one black and one light. These features, which cannot be seen under white light, make the infrared image identification have unique advantages in the field of various banknote identification. Therefore, the counterfeit device for banknotes or bills provided by the utility model performs infrared imaging on the samples to be identified by infrared reflection and transmission light sources and image sensors to produce anti-counterfeit features that cannot be seen under visible light, and then combined with the display. Observing the difference between genuine and fake banknotes, the imaging structure of the whole device is simple, and the infrared image information is rich, which can meet the requirements of counterfeiting banknotes and other bills. Using this method to achieve the purpose of anti-counterfeiting improves the reliability of counterfeiting to a certain extent .

Description of drawings

Fig. 1 is the anti-counterfeiting device of banknotes or bills provided by the utility model;

FIG. 2 is a schematic diagram of the infrared transmission light source shown in FIG. 1 .

Detailed ways

In order to make the technical problems, technical solutions and beneficial effects to be solved by the utility model clearer, the utility model will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model, and are not intended to limit the utility model.

Infrared is the light outside the red light in visible light. It is a kind of light invisible to the human eye. In the electromagnetic spectrum, the region with a wavelength range of 0.7-1000 μm is called the infrared spectral region, and the corresponding frequency range is roughly 4×10 ¹⁴ - 3×10 ¹¹ Hz. Infrared radiation is divided into four regions: near-infrared, mid-infrared, mid-far infrared, and far-infrared, and the near-infrared region is near visible light. And the light source of the counterfeit device provided by the utility model adopts the near-infrared band.

There are many types of infrared light sources, and the commonly used ones are: electrothermal light sources (such as incandescent lamps), gas discharge light sources (such as high-voltage xenon lamps), semiconductor light sources (such as light-emitting diodes) and infrared laser light sources (such as gallium arsenide laser diodes). The incandescent lamp uses electric current to heat the filament to make it incandescent and emit light. Its biggest disadvantage is that it contains visible light components, that is, there is a red burst, and its service life is short. Xenon lamp is a high-power light source manufactured by using infrared radiation produced by the discharge of high-pressure gas xenon. It is a high-current arc discharge lamp whose distribution is close to the solar spectrum. The laser light source has the advantages of monochromaticity, directionality and high intensity. Considering the cost and use effect, the counterfeit device uses an infrared LED array light-emitting unit as an infrared reflection light source, and a combination of an infrared light source and a light guide plate printed with diffused dots as an infrared transmission light source. These two kinds of infrared light sources ensure the light intensity and make the illumination uniform. Of course, the infrared reflection light source can be used alone, the infrared transmission light source can be used alone, or both the infrared reflection light source and the infrared transmission light source can be used simultaneously.

Considering the imaging method, there are two main ways to obtain near-infrared images: transmission imaging and reflection imaging. Transmission imaging (generally with a wavelength of 700-1100nm) refers to the image formed by placing the sample to be tested between the light source and the detector. The detector detects the transmitted light or the light that interacts with the sample molecules. Reflection imaging places the detector and light source on the same side of the sample, and the detector detects light that is reflected back by the sample in various ways. Specific to banknotes and bills, the transmitted light intensity of banknotes and bills is related to the absorption coefficient, thickness and reflection coefficient of the surface. Due to the strictness of the production process (especially banknotes), the thickness of banknotes and bills is strictly consistent, and the material of the paper is very Stable, but because the patterns on the surface of banknotes and bills are various, the inks on the patterns have different absorption rates for infrared. Therefore the transmitted and reflected light intensity is different. Banknotes and bills form a complete color pattern under white light, but there are many unique phenomena in the imaging of banknotes and bills under infrared light: 1) concave-convex patterns; 2) incomplete patterns with one black and one light. These invisible features under white light make infrared image identification unique advantages in the field of various banknote and bill identification. Use this method to achieve the purpose of anti-counterfeiting.

Please refer to Fig. 1, the authenticating device provided by the utility model comprises infrared transmission light source 2 and/or infrared reflection light source 5, image sensor 6, optical lens 7, computer and display 8, wherein, infrared transmission light source 2 is connected with a transmission light control Switch (not shown in the figure), for controlling the switch of the infrared transmission light source 2, the infrared reflection light source 5 is connected with a reflected light control switch (not shown in the figure), during specific work, the transmitted light control switch and the reflected light control switch Control the infrared transmission light source 2 and the infrared reflection light source 5 to work successively. The light emitted by the infrared transmission light source 2 is transmitted to the optical lens 7 after being transmitted by the sample to be identified (banknote or bill), and the light emitted by the infrared reflective light source 5 is also emitted to the optical lens 7 after being emitted by the sample to be identified (banknote or bill) , these transmitted light and reflected light all carry sample information, and the optical lens 7 is used to image the light of the infrared transmission light source 2 transmitted by the sample to be identified or the light of the infrared reflection light source 5 reflected by the sample to be identified on the image sensor 6 Converted by the image sensor 6 into an electrical signal containing image information, the image sensor 6 transmits the collected image information to a computer connected to it, and the computer further displays it on a display, and manually judges whether there is a fake sample. Of course, the image of the standard sample can also be stored in the computer in advance, and then after the image of the sample to be identified is collected by the computer, it is compared with the image of the standard sample through a software program to realize automatic counterfeiting, wherein the image sensor 6 can be It is realized by CCD (Charge Coupled Device, Charge Coupled Device) image sensor, CMOS (Complementary Metal Oxide Semiconductor, Complementary Metal Oxide Semiconductor) sensor, etc.

Considering that the images under the infrared may not be taken when the ambient light is strong, in order to avoid the interference of visible light, a dark box 4 must be designed, and the infrared transmission light source 2 and/or the infrared reflection light source 5, the image sensor 6, and the optical lens 7 are placed here. Camera Obscura 4.

Simultaneously, this dark box 4 also can provide convenience for the installation of the light source and the sample to be identified. The clamping plate 3 is used to clamp the sample to be identified. The clamping plate 3 is used to fix the sample to be identified and ensure the flatness of the sample. In addition, the material of the clamping plate 3 must have good light transmission, which will not affect the infrared light source of the system. The illumination effect can ensure the quality of the collected images, for example, it can be realized by using an acrylic plate. Since the infrared transmission light source needs to be installed at the bottom of the dark box 3, and the sample holding plate is fixed at a certain height and can be easily taken out is an important problem that needs to be solved. Therefore, the stage 1 is composed of upper and lower parts, the lower part is fixed at the bottom of the cassette, the lower space is used to install the infrared light guide plate and the white light transmission light source, and the middle through hole part of the upper part is used to install the clamping panel.

The camera obscura 4 and the stage 1 are processed by wooden splints. The advantage of using wooden materials is that they are easy to process and convenient for the installation of the light source. The clamping plate 3 is made of upper and lower two acrylic plates. Infrared reflective light source 5 can be selected several infrared light-emitting diodes to form a light-emitting matrix. The current of a single LED is 20mA, the center wavelength is 850nm, and the narrow-band distribution, half-peak bandwidth is about 40nm, which is the sensitive spectral range of ordinary cameras.

The structure of the infrared transmission light source 2 is shown in Figure 2. It consists of a diffusion film 21, a diffusion network point 22, a light guide plate 23, an upper total reflection film 24, an infrared light source 25 and a lower total reflection film 26, wherein the light guide plate 23 can be made of acrylic glass Made, the diffusion dot 22 is a highly reflective ink dot structure printed on the bottom surface of the light guide plate 23, the upper total reflection film 24 is pasted on the upper surface of the light guide plate 23 and corresponds to the position of the infrared light source 25, and the diffusion film 21 is pasted on The upper surface of the light guide plate 23 is at least at positions other than the upper total reflection film 24 , of course, the diffusion film can also be covered to the position where the total reflection film 24 is located, and the lower total reflection film 26 is pasted on the lower surface of the light guide plate 23 .

The infrared light source 25 is composed of several LED lights with a wavelength of 850nm, which are evenly distributed on the side of the light guide plate 23. FIG. 2 shows the structure of the infrared light source 25 by taking the LED lights distributed on the two long sides of the light guide plate 23 as an example, wherein The side surface of the light guide plate 23 is provided with a plurality of recessed parts, and a plurality of infrared LED lamps are respectively arranged in the plurality of recessed parts. The light guide plate 23 is designed by adding diffusion dots, that is, the highly reflective ink is printed on the bottom surface of the light guide plate in the form of dot printing to form diffusion dots 22. The diffusion dots 22 contain some tiny structures. When the LED lights on the side of the infrared light source 25 When the emitted light hits the diffusion dots 22, the light beam will be scattered and spread in all directions of the light guide plate 23. When the angle of the light is smaller than the critical angle of total reflection, the light will be transmitted from the surface of the light guide plate 23. In this embodiment, the part near the infrared light source 5 is designed to be small and sparse due to the dense light rays; The size of the diffusion network point is smaller than the size of the diffusion network point away from the infrared light source 25, and the density of the diffusion network point near the infrared light source 25 is smaller than the density of the diffusion network point away from the infrared light source 25, so the light can be evenly distributed on the surface of the light guide plate 23.

The working process of the infrared transmission light source 2 is described as follows: the light emitted by the LED lamp is scattered to all sides, but due to the repeated reflection of the upper total reflection film 24, most of the light scattered on the upper and lower sides of the light guide plate 23 finally enters the light guide plate from the side 23. When the light enters the light guide plate 23 and hits the diffuser dots 22, it will be scattered, which makes the light propagate in all directions of the light guide plate 23. When the angle of the light is smaller than the critical angle of total reflection, the light will flow from the upper surface of the light guide plate 23. shoot. Since the diffuser dots 22 near the light source are designed to be small and sparse, and the diffuser dots 22 away from the light source are designed to be large and dense, the light can be evenly distributed on the surface of the light guide plate 23 . At the same time, due to the effect of the diffusion film 21 on the upper surface, the emitted light becomes atomized, which reduces the difference between brightness and darkness, and improves the uniformity of the emitted light. The function of the lower total reflection film 26 under the light guide plate 23 is to reflect the light emitted from the lower surface of the light guide plate 23 back to the light guide plate 23, so as to improve the utilization rate of light energy and make the emitted light intensity greater.

In this embodiment, considering the role played by the upper total reflection film 24 and the lower total reflection film 26, at least the part corresponding to the infrared light source 25 in the upper total reflection film 24 and the lower total reflection film 26 is made of aluminum with higher reflection quality. film, and the rest of the lower total reflection film 26 can be realized by using other relatively low-cost total reflection films.

This counterfeit identification device conducts infrared transmission and/or reflection imaging on various banknotes and bills, and uses the obvious difference in the infrared spectra of authentic and counterfeit samples to identify counterfeit banknotes or bills. The imaging structure is simple, and the infrared image information is rich. Pseudo-reliability is high.

The above descriptions are only preferred embodiments of the present utility model, and are not intended to limit the present utility model. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present utility model shall be included in this utility model. within the scope of protection of utility models.

Claims (10)

1. A device for authenticating banknotes or bills, characterized in that it comprises: Infrared transmitted light source and/or infrared reflected light source; A transmitted light control switch connected to the infrared transmission light source and/or a reflected light control switch connected to the infrared reflection light source; Image Sensor; An optical lens that images the light of the infrared transmission light source transmitted by the sample to be identified or the light of the infrared reflection light source reflected by the sample to be identified on the image sensor; a computer connected to the image sensor; A monitor connected to said computer. 2 . The device for authenticating banknotes or bills according to claim 1 , wherein the infrared transmission light source and/or infrared reflection light source, the image sensor, and the optical lens are placed in a dark box. 3 . 3. The device for authenticating banknotes or bills as claimed in claim 2, wherein a stage is provided at the bottom of the dark box, and the infrared transmission light source is installed on the bottom of the stage, and the stage There is a clamping plate for clamping the sample to be identified. 4. The device for authenticating banknotes or bills according to claim 3, characterized in that, the clamping plate is an acrylic plate. 5. The device for authenticating banknotes or bills according to claim 1, wherein the infrared reflective light source is an infrared LED array light emitting unit. 6. The counterfeiting device for banknotes or bills as claimed in claim 1, wherein said infrared transmission light source comprises a light guide plate printed with diffuse dots, an infrared light source arranged on the side of said light guide plate, An upper total reflection film is pasted on the upper surface of the light guide plate corresponding to the position of the infrared light source, and a diffusion film is pasted on the upper surface of the light guide plate at least at positions other than the upper total reflection film; on the light guide plate The lower surface is pasted with a lower total reflection film. 7 . The device for authenticating banknotes or bills according to claim 6 , wherein the upper total reflection film is an aluminum film, and the lower total reflection film is at least a part corresponding to the infrared light source. 7 . 8. The device for authenticating banknotes or bills according to claim 6, characterized in that, on the light guide plate, the size of the diffused dots close to the infrared light source is smaller than the size of the diffused dots far away from the infrared light source. 9 . The device for authenticating banknotes or bills according to claim 6 , characterized in that, on the light guide plate, the density of diffused dots close to the infrared light source is smaller than the density of diffused dots far away from the infrared light source. 10 . 10. The device for discriminating counterfeit banknotes or bills as claimed in claim 6, wherein said infrared light source comprises several infrared LED lamps; the side of said light guide plate is provided with several recessed parts; said several infrared LED lamps are One pair is arranged in the plurality of recessed parts.

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