RU139535U1 - OPTICAL-ELECTRONIC DEVICE EXPRESS CONTROL OF AUTHENTICITY OF PROTECTIVE HOLOGRAMS - Google Patents

Abstract

1. An optical-electronic device for express-checking the authenticity of protective holograms, including an optical recording channel, consisting of a semiconductor laser mounted on the optical axis, a collimating optical system directing the laser radiation to a protective hologram, and a matrix photodetector of signals reflected from the protective hologram, and also a computer for processing by spatial frequency analysis of signals from a matrix photodetector, characterized in that it further comprises t (N-1) -optical recording channels for authenticating security holograms on a controlled document, where N≥2, in each optical recording channel there are emitters with different wavelengths of visible and near infrared radiation; equipped with an additional guidance channel, consisting of a projection lens, the mth number of white light LEDs mounted around the projection lens at an angle to the optical axis, and its matrix photodetector; optical recording channels and a guidance channel are structurally combined into a single compact optical head, which is equipped with an automated system of its linear movement relative to the controlled document. 2. The device according to claim 1, characterized in that each optical recording channel contains four emitters with laser diodes emitting at wavelengths λ = 0.405 μm, λ = 0.532 μm, λ = 0.65 μm, λ = 0.85 μm, four control units for the indicated laser diodes, four optical fibers optically coupled to the indicated laser diodes, tip,

Description

Technical field

The utility model relates to the field of creation of optical-electronic devices for recognition, identification and authenticity of diffractive and hologram protective optical elements (hereinafter DOZE-GOZE), which form the basis of protective holograms (ZG) located on documents and transparent laminating films, during the operational control of documents , as well as technical and forensic research.

State of the art

Known devices for the diagnosis and identification of DOZE-GOZE on holograms and documents. Consider the following devices that are closest in technical essence to the claimed utility model.

A device is known, described in US patent No. 4131337 "Comparision reader for holographic identification cards" (IPC G02B 27/02; G03H 1/00; G03H 1/22; G07D 7/12; G07F 7/12; G06K 9/08; publ. 12/26/1978). In the device, the authentication card is authenticated by comparing the image printed on the card itself by the printing method with the image recovered from the hologram using a laser emitter. The hologram, in turn, contains a registered image printed on the card by printing. Thus, images are alternately displayed on the matte screen of the device: a) created optically from the information area of the card by the printing method; b) the image restored from the hologram. The optical branches of the device are configured in such a way that the images obtained by the above method have the same size and brightness. If the card is not falsified, then the alternating images will be almost the same, and the human controller will not notice a mismatch in the picture on the matte screen. If the images are different, then this is easily determined by the human controller, and the conclusion is made about the falsification of the identification card.

The disadvantages of this device include:

1) the decision on the authenticity of the card is made by the human operator, and not automatically by the device itself;

2) it is not possible to register and save the image recovered from the hologram;

3) the device can only control a certain type of identification cards with a hologram applied to them.

A device is known, described in US patent No. 7925096 "Method and apparatus for validating holograms" (IPC G06K 9/76, publ. 04/12/2011). It is proposed to scan a document containing a hologram in the device at various angles, namely: to use several sources of illumination when scanning a hologram or several radiation detectors. The hologram images obtained under different conditions of illumination and observation (at least two positions of the sources or two positions of the radiation receivers) are transmitted to the image processing unit, which compares them by pixel-by-pixel subtraction of one from the other and, based on the comparison of the value of the obtained difference with the threshold value, a decision is made the true or fake nature of the DOE-GOZE: if the difference value exceeds the threshold, then the hologram is considered genuine, otherwise the hologram is fake and contains aschy its paper is derived from the circulation. A variant of the device is described, in which more than two radiation sources can be used, installed at different angles to the document with a hologram, and the image is recorded by one receiver. Moreover, in the proposed device, a single radiation source can be used and the image from the hologram is recorded by several receivers installed at different angles. A variant of the device is described where the radiation receiver is single and stationary, and the document under investigation and the radiation source are rotated from the first angle to the second

The disadvantages of this device include:

1) the lack of independent linear movement of the investigated object relative to the sources and receivers of radiation;

2) the inability to control hidden holographic images;

3) the inability to control diffractive protective trace elements contained in the hologram.

A device is known, described in US patent No. 7672475 "Method and apparatus for verifying a hologram and a credit card" (IPC G06K 9/00; G06K 9/74; G06K 9/76; G07D 7/12, publ. 02.03.2010) . The device suggests highlighting a credit card containing a hologram with several LED radiation sources at different angles. Hologram images are recorded by several CCD cameras. The first step in authenticating is comparing the sizes of the monitored and reference holograms, as well as checking the geometric location of the hologram relative to the credit card. If these parameters satisfy the requirements, then the control continues, if there are unacceptable differences from the standard, then the credit card is recognized as fake. At the next control stage, the hologram images obtained under different conditions of illumination and observation are transferred to an electronic processing unit, which compares them by pixel-by-pixel subtraction of one from the other, and based on comparing the value of the obtained difference with the threshold value of the difference, a decision is made on the true or fake nature of the hologram.

The disadvantages of this device include:

1) a decrease in the signal-to-noise ratio due to the operation of subtracting one image from another;

2) the inability to control hidden holographic images;

3) the inability to control diffractive protective trace elements contained in the hologram;

4) the device can only control a certain type of identification cards with a hologram applied to them.

As the closest analogue (prototype), the closest in technical essence to the claimed utility model device according to US patent No. 6832003 "Method and apparatus for reading and verifying holograms" (IPC G06K 7/10; G06K 9/00; G07F 7/08; G03H 1/22; G06K 19/06; G06K 9/76, publ. 14.12.2004). The device consists of a semiconductor laser, a collimating optical system, cube-prism beam splitters directing the laser radiation to a protective hologram, and a photodetector array. There is also a computer for processing images of diffraction distribution obtained as a result of diffraction on the security element of the hologram under test, by the method of spatial frequency analysis or spectrum. In this device, the radiation from the laser diode using optical elements is focused in the plane of the hologram security element of the identification card. The protective element is fully or partially reflective, so that the radiation diffracted on it is reflected and, using a translucent mirror, is directed to the photodetector array. The picture of the diffraction distribution (spatial spectrum) in the plane of the radiation receiver directly depends on the diffraction structure on the protective element and almost uniquely identifies it. It is registered and stored in the computer. If a picture close to the reference picture stored in a computer is restored when the specified area of the checked protective hologram is illuminated in the plane of the matrix photodetector, it can be stated that the identification card is authentic. In the prototype, to increase the reliability of identification, sequential reading of patterns of diffraction distribution is carried out from several areas of the hologram during its movement relative to the device.

The disadvantages of the prototype device are:

1) the device does not have the ability to register macro images of diffraction and hologram optical security elements;

2) the device does not have the ability to control the document in several zones at the same time, which leads to a significantly longer control time.

Utility Model Disclosure

The objective of the utility model is to create a more time-efficient optical-electronic device for express verification of the authenticity of GBs (and their DOZE-GOZE) and documents with them.

The solution to the problem was made by the development of an optical-electronic device for express-authenticity of protective holograms (OEU EKZPG), the principle of which is based on the analysis of the recorded spatial-frequency spectra (PES) of the microstructures of holographic images in the ZG printed on documents, including in civil passports. An optical-electronic device for express-checking the authenticity of protective holograms includes an optical recording channel consisting of a semiconductor laser mounted on the optical axis, a collimating optical system directing the laser radiation to the protective hologram, and a matrix photodetector of signals reflected from the protective hologram, as well as a computer for processing by the method of spatial-frequency analysis of signals from a matrix photodetector. Moreover, the device further comprises (N-1) -optical registration channels for authenticating security holograms on a controlled document, where N≥2. Each optical recording channel has emitters with different wavelengths of radiation of the visible and near infrared range. The device is also equipped with an additional guidance channel, consisting of a projection lens, the mth number of white light-emitting diodes mounted around the projection lens at an angle to the optical axis, and its own photodetector array. The optical recording channels and the guidance channel are structurally combined into a single compact (possibly even portable) optical head, which is equipped with an automated system for its linear movement relative to the document being controlled.

In a specific embodiment, each optical recording channel contains four emitters with laser diodes emitting at the wavelengths of the visible and near infrared ranges λ ₁ = 0.405 μm, λ ₂ = 0.532 μm, λ ₃ = 0.65 μm, λ ₄ = 0, 85 microns, four control units for the indicated laser diodes, four optical fibers optically coupled to the indicated laser diodes, a tip combining optical fibers and introducing radiation into the collimating optical system of the recording channel, and an optical fiber washer in the plane of the collimating optical system.

To optimize the work, the optical recording channels in the optical head are installed along a line parallel to the long side of the document under study, which allows optimally increasing the area and speed of processing the document.

The device also has the ability to automatically move the optical head along linear coordinates in a plane parallel to the document being monitored.

List of figures

FIG. 1 - Functional diagram of an optical-electronic device for express control of the authenticity of protective holograms (OEU EKPZG);

FIG. 2 - Functional diagram of a unified i-th (from 1 to N) optical recording channel;

FIG. 3 - Functional diagram of the guidance channel.

Utility Model Implementation

The principle of operation of the OECD EPRSG is based on a comparative analysis of the recorded spatial frequency spectra (PES) of the microstructure of holographic images in the 3D printed on passport documents. The essence of the analysis of PES HRs by the proposed OECD EEPG consists in obtaining the PES of the analyzed MH, the description of the PES of the MH using integral and point characteristics and the identification of the analyzed MH by the correlation recognition method by comparing the characteristics of the PES of the analyzed and reference MH. To do this, it is enough to illuminate the GB with laser radiation, construct a PSH of the GB, register it with a matrix photodetector of radiation and process it in a computer using the appropriate processing algorithms.

The functional diagram of the OECD EEPG is shown in FIG. 1. In the diagram, thin arrows indicate electrical connections between components, thickened arrows indicate optical radiation.

Structurally, the device with OEU EKPZG 8 has a rectangular case with a lodgement 6, on which the controlled document 5 is placed. An optical head 4 is fixed in the housing, which moves along the controlled document 5, ensuring its linear scanning. Scanning is implemented using an automated linear displacement system 7. The optical head 4 contains a guidance channel 3 and optical registration channels 1, 2, ... i, ..., N for authenticating a ZG with a DOE-GOZE. In computer 9, the information obtained from the guidance channel 3 and the optical registration channels is processed, followed by calculation and generation of the final results of the authenticity verification of the 3D document.

An important feature of the device is the possibility of simultaneous monitoring of several DOZE-GOZE in the PG located on the document to be monitored, or the control of the PG with the DOZE-GOZE of significant size in several zones. To realize this possibility, the optical head includes N unified optical registration channels (the circuit in Fig. 2) installed along a line parallel to the long side of the document under study. In a specific embodiment, each optical recording channel consists of four controlled radiation sources 21 ... 24, four optical fibers 31 ... 34 and a collimating lens 37 for focusing coherent radiation in the plane of the document being monitored 5. Laser diodes (LD) are used as radiation sources of the identification system 21 ... 24 with fiber-optic outputs with uniform wavelengths of radiation of the visible and near infrared (IR) range - 0.405, 0.532, 0.65, 0.85 μm, with a radiation power of 5 mW to 20 mW. Radiation at several wavelengths is required to cover the DOE-GOZE with different spatial frequencies of diffraction gratings. Laser diodes 21 ... 24 are controlled using the corresponding control units 11 ... 14. The radiation from each laser diode 21 ... 24 is transmitted through the corresponding optical fiber 31 ... 34 and, passing through the collimating lens 37, falls on the surface of the controlled document 5, placed on the cradle 6. The input of radiation from the optical fiber into the collimating lens 37 is realized using an optical connector 36. For this, all four optical fibers 31 ... 34 are combined using a ceramic tip 35. Each optical recording channel is equipped with its own fiber-optic washer 38, which serves to display diffraction the distribution from the controlled MH and is installed along the rays in diffracted light, reflecting from the MH behind the collimating lens 37. The fiber optic washer 38 has a hole in the center in which the collimating lens 37 is placed. A unified matrix photodetector 39 is used as a radiation receiver. Images, recorded by the matrix photodetector 39, transmit to the computer 9.

The guidance channel (the circuit in Fig. 3) is designed to position the optical head relative to the 3D document by combining and comparing the image of the 3D image received from its unified matrix photodetector 39, with the image of the standard 3D image stored in the database of 3D samples in the computer 9. In the guidance channel controlled document 5, placed on the lodgement 6, illuminate the LED backlight system 40. The backlight system 40 consists of the m-th number of white light LEDs located around the lens 41. That th LED allows you to monitor the location of the image at the same time the MO with diffraction gratings having different orientations. The image of the controlled document 5 using the lens 41 is projected onto the matrix photodetector of the radiation 39 of the guidance channel and is also transmitted to the computer 9 for further processing.

The technical result of a utility model with specific technical parameters is the ability to check documents containing a DOE-GOZE of various sizes, including up to 125 × 88 mm, or containing several DOZE-GOZE, the ability to isolate and document the characteristic features inherent in the studied DOZE-GOZE, and the ability to automatically move the optical head along linear coordinates in a plane parallel to the document being controlled, within the document area.

The implementation of this utility model provides the possibility of express control of the authenticity of the DOZE-GOZE in the SG on documents. Moreover, due to the fact that the optical head includes N identical optical registration channels, the device is capable of simultaneously controlling several ZGs located on the document at once. In this case, the document processing area increases to 2 ... 3 times, and the processing speed also increases to 2 ... 3 times, and the processing time of the passport page with the GP can be about 10 seconds.

Claims (4)

1. An optical-electronic device for express-checking the authenticity of protective holograms, including an optical recording channel, consisting of a semiconductor laser mounted on the optical axis, a collimating optical system directing the laser radiation to a protective hologram, and a matrix photodetector of signals reflected from the protective hologram, and also a computer for processing by spatial frequency analysis of signals from a matrix photodetector, characterized in that it further comprises t (N-1) -optical recording channels for authenticating security holograms on a controlled document, where N≥2, in each optical recording channel there are emitters with different wavelengths of visible and near infrared radiation; equipped with an additional guidance channel, consisting of a projection lens, the mth number of white light LEDs mounted around the projection lens at an angle to the optical axis, and its matrix photodetector; The optical registration channels and the guidance channel are structurally combined into a single compact optical head, which is equipped with an automated system for its linear movement relative to the document being controlled. 2. The device according to claim 1, characterized in that each optical recording channel contains four emitters with laser diodes emitting at wavelengths λ ₁ = 0.405 μm, λ ₂ = 0.532 μm, λ ₃ = 0.65 μm, λ ₄ = 0.85 μm, four control units for the indicated laser diodes, four optical fibers optically coupled to the indicated laser diodes, a tip combining the optical fibers and introducing radiation into the collimating optical system of the recording channel, and an optical fiber washer installed in collimating optical plane tion system. 3. The device according to claim 1, characterized in that the optical recording channels in the optical head are installed along a line parallel to the long side of the document under study. 4. The device according to claim 1, characterized in that it has the ability to automatically move the optical head along linear coordinates in a plane parallel to the document being monitored.

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