Authenticity determination system

Abstract

To provide a highly popular authenticity determination system.SOLUTION: An authenticity determination system 1 performs the authenticity determination of an ID card 10. The authenticity determination system 1 scans the ID card 10 by a scanner and includes: a reading device 2 that acquires an image of the ID card 10; and an authenticity determination device 3 that has authenticity determination means that performs the authenticity determination of the ID card 10 by step parts that lines of a printed part has, based on an image of the printed part of the ID card 10 by the thermal transfer method. The reading device 2 acquires an image of the printed part of the ID card 10 by receiving light from the ID card 10 with photo detectors of the scanner each time the photo detectors make a relative displacement in a sub-scanning direction against the ID card 10 by a shorter distance than a length in the sub-scanning direction of the photo detectors.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an authenticity determination system for determining the authenticity of an identification card. To Regarding. [Background technology]

[0002] Financial institutions, mobile phone carriers, and other institutions require identity verification by presenting an ID card (personal identification) such as a driver's license when signing a contract, but there has been an increase in cases where ID cards have been forged or altered in order to sign contracts under false names.

[0003] ID cards such as driver's licenses are generally produced using thermal transfer printing, but when counterfeiting or altering ID cards, they are often printed using inkjet printers, which are the most readily available and have high resolution.

[0004] Therefore, Patent Document 1 describes a method of determining authenticity using an image of a driver's license or the like based on a stepped portion of a line printed by a thermal transfer method. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2019-117549 A Summary of the Invention [Problem to be solved by the invention]

[0006] As described above, in order to determine the authenticity of a driver's license or the like from an image, a high-resolution reading device is required, but such reading devices are expensive, posing a problem in terms of widespread use.

[0007] The present invention has been made in consideration of the above problems, and provides a highly popular authenticity determination system. M The purpose is to provide. [Means for solving the problem]

[0008] The first invention for solving the above-mentioned problems is an authenticity determination system for determining the authenticity of an identification card, comprising: a reading device that scans the identification card with a scanner and obtains an image of the identification card; and an authenticity determination device having an authenticity determination means that determines the authenticity of the identification card based on an image of the printed portion of the identification card printed by a thermal transfer method, using a step portion of a line in the printed portion, wherein the reading device obtains an image of the printed portion of the identification card by receiving light from the identification card with the light receiving element of the scanner each time the light receiving element moves relative to the identification card in the sub-scanning direction by a first distance that is smaller than the length of the light receiving element in the sub-scanning direction.

[0009] In this invention, by utilizing the appearance of a step portion peculiar to the thermal transfer method originating from the thermal head element of the thermal transfer printer in the portion printed by the thermal transfer method and determining the authenticity of the identification card based on this step portion, it is possible to distinguish an identification card counterfeited by an inkjet printer, etc. from a fake. In addition, in this invention, when acquiring an image of the printed portion, the identification card is scanned with high precision while the light receiving element of the scanner is moved in small increments, so there is no need to use an expensive high-resolution scanner, the system configuration becomes inexpensive and the system becomes more widespread.

[0010] The reading device acquires an entire image of the identification card by receiving light from the identification card with the light receiving element of the scanner each time the light receiving element moves relative to the identification card in the sub-scanning direction by a second distance greater than the first distance, and it is desirable that the authenticity determination device has an extraction means for extracting the printed portion from the entire image, and the reading device receives position information of the printed portion from the authenticity determination device and acquires an image of the printed portion. In the present invention, the printed portion used to determine authenticity is extracted from the entire image of the identification card obtained by scanning the identification card more roughly than when the image of the printed portion was obtained, and high-resolution scanning can be performed on only that printed portion as described above, thereby contributing to the efficiency of inspection by limiting the portion of the identification card that is scanned with high resolution.

[0011] It is desirable that the authenticity determining means determines whether or not the identification card is a genuine identification card in which the printed portion was printed by a thermal transfer printer of a specified dpi, based on the width of the step in the sub-scanning direction. Since the width of the step mentioned above varies depending on the dpi (resolution) of the thermal transfer printer, by using this width to determine authenticity, if a thermal transfer printer with a different dpi from that used to print the genuine identification card is used for the counterfeit, it can be determined that the counterfeit is a counterfeit.

[0012] The authenticity determination device has an image processing means which performs noise removal by binarizing an image of the printed portion of the identification card and setting the pixel value of the binarized image to a majority of the values ​​of the pixel in question and the pixels on either side of the pixel in the sub-scanning direction, and it is desirable that the authenticity determination means performs the authenticity determination from the image after noise removal. This makes it possible to remove noise that appears in the image obtained by scanning the printed portion, and to perform authenticity determination with high accuracy.

[0013] The printed portion is, for example, a predetermined specific character. In identification cards such as driver's licenses, characters such as the holder's birth date, address, and the date of issue of the identification card are printed using a thermal transfer method, and the authenticity of the identification card can be determined by the stepped portions of these characters. In the present invention, by extracting specific characters that are prone to having stepped portions, it is possible to perform authenticity determination with high accuracy and efficiency. Effect of the Invention

[0017] The present invention provides a highly popular authenticity determination system. M can be provided. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a diagram showing an outline of an authenticity determination system 1. [Diagram 2] FIG. 2 is a diagram showing the hardware configuration of a reading device 2. [Diagram 3]FIG. 2 is a diagram showing the hardware configuration of an authenticity determination device 3. [Figure 4] FIG. 2 is a block diagram showing the functions of the authenticity determination device 3. [Diagram 5] 1 is a diagram showing an outline of an ID card 10. FIG. [Figure 6] An example of enlarging part of the text. [Figure 7] 1A and 1B are diagrams for explaining printing by a thermal transfer printer 100. [Figure 8] 4 is a flowchart showing the process of the authenticity determination system 1. [Figure 9] FIG. 2 is a diagram for explaining scanning of an ID card 10. [Figure 10] Example of image data 4. [Figure 11] 11 is a flowchart showing a procedure for determining authenticity. [Figure 12] FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

[0020] (1. Authenticity Determination System 1) 1 is a diagram showing an overview of an authenticity determination system 1 according to an embodiment of the present invention. The authenticity determination system 1 determines the authenticity of an ID card 10, and includes a reading device 2 and an authenticity determination device 3. The reading device 2 and the authenticity determination device 3 are communicatively connected by wireless communication means such as Bluetooth (registered trademark), but may also be connected by wire.

[0021] The reading device 2 reads an image of the ID card 10 by scanning the ID card 10 with a scanner, and transmits the image to the authenticity determination device 3 .

[0022] Fig. 2 is a diagram showing a hardware configuration of the reading device 2. As shown in Fig. 2, the reading device 2 includes a reader 21, a scanner 22, a computer 23, and a communication unit 24. Although not specifically shown, the reading device 2 also includes a battery and the like.

[0023] The reader 21 reads the IC chip of the ID card 10. As the reader 21, a known card reader or the like can be used.

[0024] The scanner 22 scans the ID card 10 and acquires an image of the ID card 10. The scanner 22 has a scanner head with light receiving elements arranged in a row, and acquires an image of the ID card 10 by shining light on the ID card 10 while moving the scanner head relative to the ID card 10 and receiving light reflected from the ID card 10 with each light receiving element. The arrangement direction of the light receiving elements and the movement direction of the scanner head are perpendicular on a plane, the former being called the main scanning direction (of the scanner 22) and the latter being called the sub-scanning direction (of the scanner 22).

[0025] The computer 23 is a control device that controls each part of the reading device 2 and executes the processes described below of the reading device 2. A program that executes the processes described below is stored in the storage area of ​​the computer 23. Note that instead of the computer 23, an FPGA (field-programmable gate array) or the like can be used.

[0026] The communication unit 24 communicates with the authenticity determination device 3 via wireless communication means such as Bluetooth (registered trademark).

[0027] Returning to the explanation of Fig. 1, the authenticity determination device 3 determines the authenticity of the ID card 10 based on an image of the ID card 10.

[0028] Fig. 3 is a diagram showing a hardware configuration of the authenticity determination device 3. As shown in Fig. 3, the authenticity determination device 3 can be realized by a computer configured by connecting a control unit 31, a storage unit 32, a display unit 33, an input unit 34, a communication control unit 35, etc. via a bus or the like. However, the authenticity determination device 3 is not limited to this, and various configurations can be used as appropriate.

[0029] The control unit 31 is composed of a CPU, a ROM, a RAM, etc. The CPU loads programs related to the processing of the authenticity determination device 3 stored in a storage medium such as the memory unit 32 or ROM into a work area on the RAM and executes them. The ROM is a non-volatile memory, and permanently stores programs such as the boot program and BIOS, data, etc. The RAM is a volatile memory, and temporarily stores programs and data loaded from the memory unit 32, ROM, etc., and also has a work area used by the control unit 31 to perform various processes.

[0030] The storage unit 32 is a hard disk drive, a solid state drive, a flash memory, or the like, and stores programs executed by the authenticity determination device 3 in the processes described below, data necessary for executing the programs, an OS, etc. These programs and data are read out and executed by the control unit 31 as necessary.

[0031] The display unit 33 includes a liquid crystal display or the like. The input unit 34 is used to input various settings to the authenticity determination device 3 . The communication control unit 35 is a communication interface that mediates wireless communication, and performs communication with the reader 2.

[0032] Fig. 4 is a block diagram showing the functions of the authenticity determination device 3. As shown in Fig. 4, the authenticity determination device 3 includes an extraction means 301, an image processing means 302, an authenticity determination means 303, and the like.

[0033] The extraction means 301 is a means for extracting a specific printed portion of the ID card 10 from the entire image of the ID card 10 read by the control unit 31 of the authenticity determination device 3 using the scanner 22 of the reading device 2. This printed portion is printed using a thermal transfer method, which will be described later in detail.

[0034] The image processing means 302 binarizes the image of the printed portion read by the control unit 31 of the authenticity determination device 3 using the scanner 22 of the reading device 2, and removes noise from the binarized image.

[0035] The authenticity determination means 303 is a means for determining the authenticity of the ID card 10 by the control unit 31 of the authenticity determination device 3 based on the image after noise removal, using the stepped portion of the line in the printed portion of the ID card 10. Details of the authenticity determination will be described later.

[0036] (2. ID Card 10) In this embodiment, the ID card 10 is an identity card that is the subject of authentication. An identity card is a medium used for identity verification by financial institutions, mobile phone carriers, etc., and is, for example, a driver's license, a My Number card, a residence card, a special permanent resident card, etc.

[0037] 5 is a diagram showing an overview of an ID card 10, and is a schematic diagram showing an example of the face of the ID card 10. The ID card 10 has the holder's name 12, date of birth 13, address 14, facial image 15, issue date 16 of the ID card 10, etc. printed on a substantially rectangular card substrate 11. Although not shown, an IC chip is provided on the back side of the ID card 10.

[0038] The cardholder's name 12, date of birth 13, address 14, and issue date 16 of the ID card 10 are printed in monochrome on the card substrate 11 by a thermal transfer printer with a specified dpi (resolution) using a melting type thermal transfer method. Meanwhile, the frames and lines indicating the fields for writing the name 12, etc. are formed in advance on the card substrate 11 by a printing method other than the thermal transfer method, for example, offset printing or letterpress printing, and are called pre-printed portions.

[0039] FIG. 6(a) is an example of an enlarged portion of a character on an ID card 10 printed by thermal transfer printing, and in this embodiment, many steps B are formed in the lines of the character. Steps B are roughly L-shaped portions that appear at the outline of the line, and are formed when the character is printed by thermal transfer printing. Steps B are particularly noticeable in the curved or diagonal parts of the character. On the other hand, when the character is printed by an inkjet printer, the line becomes smooth and no clear steps are formed, as shown in FIG. 6(b).

[0040] (3. Printing ID cards 10 using thermal transfer method) Printing by the thermal transfer method is performed by a thermal transfer printer 100 shown in Fig. 7(a). In the thermal transfer printer 100, a thermal transfer ribbon 200 wound around a supply reel 101 is unwound and transported, and heat is applied to the thermal transfer ribbon 200 by a thermal head 110 along the way to transfer the transfer layer onto an ID card 10. After transfer, the thermal transfer ribbon 200 is taken up by a take-up reel 102. Character printing is performed by transferring a K (black) transfer layer onto the ID card 10 while the ID card 10 is transported by transport rollers 103.

[0041] As shown in Fig. 7(b), the thermal head 110 applies heat to the thermal transfer ribbon 200 from thermal head elements 111 provided on its underside. On the underside of the thermal head 110, multiple thermal head elements 111 are arranged in a row as shown in Fig. 7(c), and the ID card 10 is printed by controlling the on / off of heating by each thermal head element 111.

[0042] The arrangement direction of the thermal head elements 111 is perpendicular to the transport direction of the ID card 10 during printing in a plane, and is called the main scanning direction (of the thermal transfer printer 100). On the other hand, the transport direction of the ID card 10 during printing is called the sub-scanning direction (of the thermal transfer printer 100). In this embodiment, the main scanning direction corresponds to the short side direction of the ID card 10, and the sub-scanning direction corresponds to the long side direction of the ID card 10. The length Dm of the thermal head elements 111 in the main scanning direction and the length Ds of the sub-scanning direction differ depending on the dpi of the thermal transfer printer 100, and the higher the dpi, the shorter Dm and Ds become.

[0043] 7(b), in a melting type thermal transfer method, the transfer layer 202 in the range C adheres to the ID card 10, and when the thermal transfer ribbon 200 is taken up by the take-up reel 102 and separated from the ID card 10, it peels off from the base material 201 of the thermal transfer ribbon 200. This causes the transfer layer 202 to be transferred to the ID card 10, and characters are printed.

[0044] As a result, characters are printed using the size of the thermal head element 111 as a unit, and steps resulting from the thermal head element 111 are formed at the outlines of the lines, as partially shown in FIG. 7(d).

[0045] The widths a1 to a3 of the stepped portions in the main scanning direction are equal to an integer multiple n·Dm (n=1, 2, 3 . . . ) of the length Dm of the thermal head element 111 in the main scanning direction.

[0046] On the other hand, the widths b1 to b3 of the steps in the sub-scanning direction are approximately n·Ds (n=1, 2, 3...) which is an integer multiple of the length Ds in the sub-scanning direction of the thermal head element 111. We say "approximately" because when heat is applied from the thermal head element 111 to a certain range C of the transfer layer 202, the length W in the sub-scanning direction of the transfer layer 202 that peels off from the thermal transfer ribbon 200 (see FIG. 7(b)) varies and may not strictly be an integer multiple of the length Ds of the thermal head element 111 in the sub-scanning direction.

[0047] (4. Overview of the process of the authenticity determination system 1) Fig. 8 is a flowchart showing an outline of the processing of the authenticity determination system 1. S1 to S2 and S6 to S8 in Fig. 8 are processing executed by the computer 23 of the reading device 2 by controlling each part of the reading device 2, and S3 to S5 and S9 to S11 are processing executed by the control unit 31 of the authenticity determination device 3 by controlling each part of the authenticity determination device 3.

[0048] 8 is started, for example, by setting the ID card 10 in a specified position on the reading device 2 and sending a command to start the process from the authenticity determination device 3 to the reading device 2. The reading device 2 first scans the surface of the ID card 10 with the scanner 22 (S1), and sends the entire image of the ID card 10 thus obtained to the authenticity determination device 3 (S2).

[0049] 9(a) to 9(c) are diagrams for explaining scanning of S1. In this embodiment, the scanner head, in which a number of light receiving elements 221 are arranged in a row as shown in FIG. 9(a), receives light from the ID card 10 at each light receiving element 221 as it moves relative to the ID card 10 in the sub-scanning direction of the scanner 22 as shown by the arrow d in FIG. 9(b). In this embodiment, the sub-scanning direction corresponds to the long side direction of the ID card 10. The moving distance (second distance) of the scanner head (light receiving element 221) in one movement corresponds to the length D of the light receiving element 221 in the sub-scanning direction. In the following description, the main scanning direction and the sub-scanning direction refer to the main scanning direction and the sub-scanning direction of the scanner 22 unless otherwise specified.

[0050] FIG. 9(c) shows the state after scanning of a certain range is completed, and FIG. 10(a) shows an example of the image data 4 created at this time. The value V of each pixel of the image data 4 (V 11 ~V 57 ) depends on the amount of light received by the light receiving element 221 at each scanner head position. For example, the value V of each pixel in rows R1 and R2 of image data 4 corresponds to the amount of light received by each light receiving element 221 when the scanner head is at positions D1 and D2 in FIG. 9(c).

[0051] The authenticity determination device 3 receives image data 4 of the entire image of the ID card 10 (S3), and then performs a known OCR (optical character recognition) process on the image data 4 to search for and extract specific characters that have been determined in advance (S4). When the authenticity determination device 3 extracts the specific characters, it transmits position information of the character portion to the reading device 2 (S5).

[0052] In this embodiment, a search for specific characters is performed in predetermined areas a to c (see FIG. 5) on the ID card 10 in which the birth date 13, address 14, and issue date 16 are printed. The search order for the areas a to c can be determined in advance, and character extraction ends when a predetermined number of specific characters have been extracted. Here, for simplicity of explanation, the predetermined number is set to 1.

[0053] The specific characters are not particularly limited, but in this embodiment, as described later, authenticity is determined based on the steps of the lines of the characters, so characters that have curves or diagonal lines that are likely to produce steps and are often used for dates of birth 13, addresses 14, and issue dates 16 are used. Letters (numbers) such as "0", "8", "3", "2", and "4" are preferable.

[0054] When the reading device 2 receives the position information of the character portion (S6), it moves the scanner head to the character portion based on the position information and scans the character portion with high precision (S7), and transmits the image of the character portion thus obtained to the authenticity determination device 3 (S8).

[0055] 9(d) and (e) are diagrams for explaining the scanning of S7 in comparison with the scanning of S1 (FIGS. 9(b) and (c)).

[0056] In S7 as well, each time the scanner head (light receiving element 221) moves in the sub-scanning direction relative to the ID card 10, the light from the ID card 10 is received by each light receiving element 221. However, in S7, the moving distance of the scanner head at this time (first distance) is set to a length shorter than the length D of the light receiving element 221 in the sub-scanning direction, for example, 1 / 3D, as shown in FIG.

[0057] Fig. 9(e) shows the state after scanning the same range as Fig. 9(c), but the image data 4 created at this time has an increased number of columns compared to scanning S1 (see Fig. 10(a)) as a result of moving the scanner head more precisely, as shown in Fig. 10(b). Note that the value V of each pixel in columns R1 and R2 of the image data 4 in Fig. 10(b) corresponds to the amount of light received by each light receiving element 221 when the scanner head is at positions D1 and D2 in Fig. 9(e).

[0058] When the authenticity determination device 3 receives the image data 4 of the character portion (S9), it determines the authenticity of the ID card 10 using the image data 4 of the character portion (S10). This authenticity determination will be described in detail later. The authenticity determination device 3 displays the determination result on the display unit 33 (S11) and ends the process. The operator can take appropriate measures by looking at the determination result.

[0059] In addition to the above processing, the reading device 2 can read the IC chip of the ID card 10 using the reader 21 and determine whether it is a genuine IC chip and not a counterfeit, thereby enabling a more reliable determination of authenticity.

[0060] (5. Authenticity determination process) Next, the procedure of the authenticity determination process in S10 will be described with reference to Fig. 11, which is a flowchart showing the authenticity determination process in S10.

[0061] In S10, the authenticity determination device 3 first converts the image data 4 of the text portion to grayscale as necessary, and then binarizes the image data 4 (S101). Then, noise is removed from the binarized image data 4 (S102).

[0062] 12(a) is an example of image data 4 after binarization, where a value "1" indicates a black pixel and a value "0" indicates a white pixel. In S102, the value of a pixel of interest 41 in the image data 4 is set to a majority of the values ​​of the pixel of interest 41 and the pixels 42 on either side of the pixel of interest in the sub-scanning direction (the row direction of the image data 4, i.e., corresponding to the left-right direction in FIG. 12(a)).

[0063] The above process is repeated with each pixel of the image data 4 as the pixel of interest 41, thereby removing noise from the image data 4. For example, if noise (black pixels) is generated due to dust or the like on the ID card 10 as shown by reference numeral 43 in Fig. 12(a), the noise is removed (becoming a white pixel) by performing the above process with this as the pixel of interest 41, as shown in Fig. 12(b).

[0064] Next, the authenticity determination device 3 detects steps in the lines of the characters from the image data 4 after noise has been removed (S103).

[0065] The method for detecting the step is not particularly limited, but in this embodiment, for example, as shown in FIG. 12(c), the position where the pixel value changes from "0" to "1" or from "1" to "0" along the sub-scanning direction is detected as a boundary 44.

[0066] Then, as shown in Fig. 12(d), the authenticity determination device 3 calculates the distance L between adjacent boundaries 44 in the column direction (corresponding to the up-down direction in Fig. 12(d)) of the image data 4. At this time, if the position of the boundary 44 in the sub-scanning direction is the same between adjacent rows in the column direction of the image data 4 (see the boundary 44 on the right side in Fig. 12(c)), these boundaries 44 are regarded as one continuous boundary 44 as shown in Fig. 12(d).

[0067] The distance L can be calculated from the number of pixels, and if the distance L is equal to or greater than a predetermined value, the authenticity determination device 3 detects this as a step in the character and determines the distance L as the width of the step in the sub-scanning direction.

[0068] In the above example, when the position of the boundary 44 in the sub-scanning direction is the same between adjacent rows in the column direction of the image data 4, these boundaries 44 are regarded as one continuous boundary 44. However, when the difference in the position of the boundary 44 in the sub-scanning direction between adjacent rows in the column direction of the image data 4 is within a certain value, these boundaries 44 may also be regarded as one continuous boundary 44.

[0069] As described above, the authenticity determination device 3 detects one or more steps from the image data 4. Then, the number of pixels in the image data 4 corresponding to the length Ds of the thermal head element 111 (the length in the sub-scanning direction of the thermal transfer printer 100; see FIG. 7(c)) (i.e., how many pixels in the image data 4 the length Ds corresponds to) is set as a reference value S, and the width L of each step is compared with the reference value S.

[0070] If there are a predetermined number or more of stepped portions having a width L that is an integer multiple n·S (n=1, 2, 3...) of the reference value S (S104; YES), the authenticity determination device 3 determines that the character was printed by a thermal transfer printer 100 with a predetermined dpi used for printing the genuine ID card 10, and determines that the ID card 10 is genuine (S105). On the other hand, if there are no predetermined number or more of stepped portions having a width L that is an integer multiple n·S of the reference value S (S104; NO), the authenticity determination device 3 determines that the ID card 10 is not genuine (S106). Note that the "step portion having a width L that is an integer multiple n·S of the reference value S" includes a step portion whose width L is within the error range of the integer multiple n·S of the reference value S. The error range can be set arbitrarily taking into account the inspection accuracy, etc.

[0071] The above-mentioned predetermined number is not particularly limited, and may be determined in advance according to the characters extracted in S4 (see FIG. 8), for example. The above-mentioned predetermined number may also be a ratio to the number of shoulders detected in S103.

[0072] As described above, in this embodiment, a step portion specific to the thermal transfer method originating from the thermal head element 111 of the thermal transfer printer 100 appears in the portion printed by the thermal transfer method, and by determining the authenticity of the ID card 10 based on this step portion, it is possible to determine that an ID card 10 counterfeited by an inkjet printer or the like is counterfeit. In addition, in this embodiment, when acquiring an image of the printed portion, the ID card 10 is scanned with high precision while the scanner head (light receiving element 221) is moved in small increments, so there is no need to use an expensive high-resolution scanner, making the system configuration inexpensive and improving its popularity.

[0073] On the ID card 10, characters such as the holder's birth date 13, address 14, and issue date 16 of the ID card 10 are printed by a thermal transfer printer 100, and the authenticity of the ID card 10 can be determined by the stepped portions of these characters. In this embodiment, authenticity can be determined efficiently and with high accuracy by extracting specific characters that have curved lines or diagonal lines that are likely to form stepped portions.

[0074] Since the width L of the step varies depending on the dpi of the thermal transfer printer 100, in this embodiment, this width L is used to determine authenticity, so that a thermal transfer printer with a different dpi than the thermal transfer printer 100 used to print the genuine ID card 10 can be prepared for counterfeiting, and the ID card 10 counterfeited using this can also be determined to be counterfeit.

[0075] In this embodiment, the scanning of the ID card 10 in S1 (see FIG. 8) is performed roughly by making the distance the scanner head moves per time larger than that in the scanning in S7, and the printed portion used for authenticity determination is extracted from the entire image of the ID card 10 obtained in this way, and high-resolution scanning in S7 can be performed only on that printed portion, thereby contributing to the efficiency of the inspection by limiting the portion of the ID card 10 that is scanned in high resolution. However, by scanning the entire image of the ID card 10 in S1 with high resolution as in S7, it is also possible to omit the processes of S4 to S9 described above.

[0076] Furthermore, in this embodiment, as described above, the image data 4 is binarized and noise is removed, and the authenticity can be determined with high accuracy from the image data 4 after noise removal.

[0077] However, the present invention is not limited to the above embodiment. For example, in order to improve the inspection accuracy, it is possible to perform authenticity determination using a plurality of characters. However, taking into consideration the processing time, it is preferable to use about three characters. When using a plurality of characters for the determination, the above-mentioned processes of S101 to S104 are performed for each character to determine whether it was printed by the thermal transfer printer 100 with a predetermined dpi, and if the number of characters determined to have been printed by the thermal transfer printer 100 with the predetermined dpi is equal to or greater than a predetermined number, the ID card 10 can be determined to be authentic.

[0078] In addition, in this embodiment, the lines of characters printed in monochrome are used to determine authenticity, but if the printed portion is printed using a thermal transfer method, lines other than characters can also be used to determine authenticity, and color printed lines may also be used to determine authenticity.

[0079] In addition, in this embodiment, the sub-scanning direction of the scanner 22 corresponds to the long side direction of the ID card 10, but if the sub-scanning direction of the scanner 22 is the short side direction of the ID card 10, it is also possible to make a judgment using the length Dm of the thermal head element 111 (the length in the main scanning direction of the thermal transfer printer 100; see Figure 7 (c)) as a reference value, which is expected to improve the inspection accuracy.

[0080] Although the preferred embodiment of the present invention has been described above with reference to the accompanying drawings, the present invention is not limited to the above examples. It is clear that a person skilled in the art can come up with various modified or altered examples within the scope of the technical ideas disclosed in this application, and it is understood that these also naturally belong to the technical scope of the present invention. [Explanation of symbols]

[0081] 1: Authenticity determination system 2: Reading device 3: Authenticity determination device 10: ID card 22: Scanner 100: Thermal transfer printer 110: Thermal head 111: Thermal head element 221: Photodetector 301:Extraction means 302: Image processing means 303: Authenticity determination method

Claims

1. An authenticity determination system for determining the authenticity of an identification card, comprising: a reading device that scans an identification card with a scanner and obtains an image of the identification card; an authenticity determining device having an authenticity determining means for determining the authenticity of the identification card based on an image of a portion of the identification card printed by a thermal transfer method and a step portion of the line of the printed portion; having The reading device obtains an image of the printed portion of the identification card by receiving light from the identification card with a light receiving element of a scanner each time the light receiving element moves relative to the identification card in the sub-scanning direction by a first distance that is smaller than the length of the light receiving element in the sub-scanning direction.

2. the reading device receives light from the identification card with a light receiving element of a scanner, each time the light receiving element of the scanner moves relative to the identification card in the sub-scanning direction by a second distance greater than the first distance, thereby obtaining an entire image of the identification card; The authenticity determination device has an extraction means for extracting the printed portion from the entire image, 2. The authenticity determination system according to claim 1, wherein the reading device receives position information of the printed portion from the authenticity determination device and obtains an image of the printed portion.

3. The authenticity determination system according to claim 1 or claim 2, characterized in that the authenticity determination means determines whether the identification card is a genuine identification card in which the printed portion was printed by a thermal transfer printer of a predetermined dpi based on the width of the step portion in the sub-scanning direction.

4. the authenticity determination device has an image processing means for performing noise removal by binarizing an image of the printed portion of the identification card and setting a pixel value of the binarized image to a majority of values ​​of the pixel and the pixels on both sides of the pixel in the sub-scanning direction, 4. The authenticity determining system according to claim 1, wherein the authenticity determining means performs the authenticity determination from an image after noise has been removed.

5. 5. The authenticity determination system according to claim 1, wherein the printed portion is a predetermined specific character.

Images