Falsification detection device and image forming apparatus

Abstract

To make it possible to easily narrow down a document to be detected and a document whose identity is to be confirmed, to efficiently detect falsification, and to improve a falsification detection capability.SOLUTION: An image forming apparatus 1 includes: an original reading part 5 reading an image of a document to be detected; an identifier detection part 102 detecting an identifier shown by a code added to the document to be detected on the basis of a document image showing the document to be detected obtained by reading with the original reading part 5; and a falsification detection part 101 detecting whether or not the document to be detected is falsified by determining identification of the document to be detected with a registered document on the basis of the document image showing the document to be detected and information about the registered document stored to a document database 91 in association with the identifier detected by the identifier detection part 102.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a tampering detection device and an image forming device, and more particularly to a technique for detecting document tampering. [Background technology]

[0002] The following Patent Documents 1 to 3 describe technologies for detecting document tampering. For example, Patent Document 1 describes a technique in which handwriting erased by heating is made visible by a cooling process, making it possible to confirm the contents of the erased handwriting. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] U.S. Patent No. 10,412,256 [Patent Document 2] US Patent Application Publication No. 2022 / 0150377 [Patent Document 3] U.S. Patent No. 8,850,606 Summary of the Invention [Problem to be solved by the invention]

[0004] To determine whether a document has been tampered with, for example, it is sufficient to check the identity of the document to be inspected with its original document. However, when there are a large number of candidate original documents, it is not easy to narrow down the documents to be checked for identity with the document to be inspected. If the processing load for narrowing down the documents becomes too large, there is a risk that the ability to detect tampering will be reduced.

[0005] The present invention has been developed in consideration of the above circumstances, and aims to make it easy to narrow down the documents whose identity should be confirmed with the document to be inspected, to efficiently detect tampering, and to improve tamper detection capabilities. [Means for solving the problem]

[0006] A tampering detection device according to one aspect of the present invention comprises a document reading unit that reads an image of a document to be inspected; an identifier detection unit that detects an identifier indicated by a code contained in the document to be inspected based on a document image showing the document to be inspected obtained by reading by the document reading unit; and a tampering detection unit that accesses a document database that stores information about registered documents linked to unique identifiers, determines the identity of the document image with the registered document stored in the document database linked to the identifier detected by the identifier detection unit, and detects that the document to be inspected has been tampered with if it determines that there is no identity.

[0007] In addition, an image forming apparatus according to one aspect of the present invention includes the tampering detection apparatus according to the above-described one aspect of the present invention and an image forming unit that forms an image on a recording medium, and the tampering detection apparatus further includes a control unit that, when the identifier detection unit does not detect the identifier from the document to be inspected, creates a unique identifier for the document to be inspected and a code indicating the identifier, and stores the identifier and a document image indicating the document to be inspected in the document database, and when the identifier detection unit does not detect the identifier from the document to be inspected, the control unit combines the created code indicating the identifier with a document image indicating the document to be inspected, and causes the image forming unit to form the combined document image on the recording medium. [Effects of the Invention]

[0008] According to the present invention, the documents to be confirmed as identical to the document to be inspected are determined based on the identifier indicated by the code attached to the document to be inspected, making it easier to narrow down the documents in question, enabling efficient tamper detection and improving tamper detection capabilities. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a perspective view showing the appearance of an image forming apparatus according to an embodiment of the present invention; [Figure 2]1 is a functional block diagram illustrating a schematic main internal configuration of an image forming apparatus according to an embodiment of the present invention; [Figure 3] FIG. 2 is a diagram showing an example of information about registered documents stored in a document database. [Figure 4] (A) shows an example of an original document that is the source document of the document to be inspected, and (B) shows an example of the document to be inspected. [Figure 5] 10 is a flowchart illustrating an example of processing performed by a control unit in the image forming apparatus. [Figure 6] FIG. 10 is a diagram illustrating an example of information related to a registered document. DETAILED DESCRIPTION OF THE INVENTION

[0010] A tamper detection device and an image forming apparatus according to an embodiment of the present invention will be described below with reference to the drawings. Fig. 1 is a perspective view showing the appearance of an image forming apparatus according to an embodiment of the present invention. Fig. 2 is a functional block diagram showing the main internal configuration of an image forming apparatus according to an embodiment of the present invention.

[0011] The image forming apparatus 1 is a multifunction device that combines multiple functions such as a copy function, a printer function, a scanner function, and a facsimile function, and is an embodiment of an apparatus that includes a tamper detection device according to the present invention.

[0012] The image forming apparatus 1 includes a control unit 10, a document feeder 6, a document reader 5, an image forming unit 12, a fixing unit 13, a paper feeder 14, an operation unit 47, a communication unit 9, and a storage unit 8. The document reader 5 is an example of a document reader in the claims.

[0013] The document feeder 6 is configured to be openable and closable by a hinge or the like (not shown) on the top surface of the document reading unit 5, and functions as a document pressing cover when reading a document placed on a platen glass (not shown). The document feeder 6 is also called an ADF (Auto Document Feeder) or DP (Document Processor), and includes a document placement tray 61 on which documents are placed, and a document discharge tray 62 provided below the document placement tray 61. The document feeder 6 supplies documents placed on the document placement tray 61 to the document reading unit 5 one by one, and discharges the documents to the document discharge tray 62.

[0014] The document reading unit 5 includes a scanner and the like, and reads the document fed from the document feeding unit 6 or reads the document placed on the platen glass. The document reading unit 5 is also capable of sequentially reading multiple document images sent from the document feeding unit 6.

[0015] The following describes the case where a document is read by the image forming apparatus 1. The document reading unit 5 optically reads an image of a document supplied to the document reading unit 5 by the document feeding unit 6 or a document placed on the platen glass, and generates image data. The image data generated by the document reading unit 5 is stored in an image memory (not shown) or the like.

[0016] The following describes an image forming operation performed by the image forming apparatus 1. The image forming unit 12 is equipped with a photosensitive drum, charging device, exposure device, developing device, and primary transfer device for each color, and is a mechanism for forming an image on recording paper as a recording medium by secondary transfer via an intermediate transfer belt. The image forming unit 12 forms a toner image on recording paper fed from the paper feed unit 14 based on image data generated by a document reading operation, image data stored in an image memory, etc., and image data received from a computer connected via a network, to create a printed matter.

[0017] The fixing unit 13 is a fixing device equipped with a heat roller, a pressure roller, and a drive mechanism for rotating these rollers. The fixing unit 13 heats and presses the recording paper on which the toner image has been formed by the image forming unit 12 at the nip between the two rollers, fixing the toner image to the recording paper. The recording paper that has been fixed is then discharged to the discharge tray 151.

[0018] The paper feed unit 14 includes a paper feed cassette 141, a pickup roller that picks up recording paper from the paper feed cassette and feeds it to the image forming unit 12, a transport roller, a transport path, and a rotation drive mechanism for each roller.

[0019] The operation unit 47 includes various hard keys that are operated by the user, and receives instructions from the user, such as an instruction to execute an image forming operation, regarding various operations and processes that the image forming apparatus 1 can execute in response to the operation of the hard keys.

[0020] The operation unit 47 includes a display unit 473 that displays operation guides and the like to the operator. The operation unit 47 also receives input of instructions from the user based on the user's operation (touch operation) on the screen displayed on the display unit 473 via a touch panel that the display unit 473 has.

[0021] The display unit 473 is composed of an LCD (Liquid Crystal Display) or the like. When the operator touches a button or key displayed on the screen, the touch panel receives an instruction associated with the touched position. In this case, the touch panel functions as an operation unit.

[0022] The communication unit 9 is a communication interface that transmits and receives various data to and from external devices within a local area or on the Internet (for example, a document database 91 or a PC (not shown)). For example, the communication unit 9 transmits and receives data to and from a document database 91 located within a local area or on a cloud via a communication network such as a LAN or the Internet.

[0023] The document database 91 is a storage device that stores information about registered documents linked to a unique identifier. The document database 91 is a device separate from the image forming apparatus 1. However, the document database 91 may also be a storage device built into the image forming apparatus 1. In this embodiment, an example will be described in which the document database 91 is a device separate from the image forming apparatus 1.

[0024] 3 is a diagram showing an example of information about a registered document stored in the document database 91. As shown in the example in FIG. 3, information about the registered document (document name of the registered document and image data showing an image of the registered document) is stored in association with a unique identifier ID.

[0025] The storage unit 8 is a large-capacity storage device such as a hard disk drive (HDD) or a solid state drive (SSD), and stores various control programs and the like.

[0026] The control unit 10 includes a processor, a RAM (Random Access Memory), a ROM (Read Only Memory), and a dedicated hardware circuit. The processor is, for example, a CPU (Central Processing Unit), an ASIC (Application Specific Integrated Circuit), or an MPU (Micro Processing Unit). The control unit 10 includes a control unit 100, a tamper detection unit 101, and an identifier detection unit 102.

[0027] The control unit 10 functions as a control unit 100, a tamper detection unit 101, and an identifier detection unit 102 through operation by the processor in accordance with a control program, etc. stored in the storage unit 8. However, the control unit 100, etc. can also be configured by hardware circuits, without relying on operation in accordance with a control program by the control unit 10. Unless otherwise stated below, this applies to each embodiment.

[0028] The control unit 100 is responsible for overall operational control of the image forming apparatus 1. The control unit 100 is connected to the document feeding unit 6, the document reading unit 5, the image forming unit 12, the fixing unit 13, the paper feeding unit 14, the operation unit 47, the communication unit 9, and the storage unit 8, and controls the driving of these units and executes various processes required for image formation by the image forming apparatus 1.

[0029] For example, the control unit 100 controls the operation of the image forming unit 12 to execute a copy job in which an image indicated by image data of a document obtained by reading the document by the document reading unit 5 is formed on a recording medium. The control unit 100 also executes a scan transmission job in which the image data is transmitted to a predetermined personal computer via the communication unit 9.

[0030] The falsification detection unit 101 determines whether the document to be inspected is identical to a registered document stored in the document database 91, thereby detecting whether the document to be inspected has been falsified.

[0031] FIG. 4(A) shows an example of an original document that is the source document of the document to be inspected, and FIG. 4(B) shows an example of the document to be inspected.

[0032] The original document DA shown in FIG. 4(A) includes a mark M indicating that it is a confidential document. The mark M is a mark in which the character string "TOP SECRET" is enclosed in a box. The document DB to be inspected shown in FIG. 4(B) is the original document DA to which a code CD has been added. The code CD includes, as information, a unique identifier ID for identifying the original document DA. Note that a QR code (registered trademark) is used here as an example of the code CD. However, the code CD is not limited to a QR code and may be another code, such as a barcode.

[0033] Information about the original document DA (for example, image data indicating the original document DA) is linked to a unique identifier ID and stored and registered in the document database 91. That is, the information about the original document DA is stored in the document database 91 as information about the registered document DC.

[0034] The identifier detection unit 102 detects an image indicating a code CD including an identifier ID as information from the document image GD in the inspection target document DB obtained by reading by the document reading unit 5. For example, the identifier detection unit 102 analyzes the detected image indicating the code CD and identifies the identifier ID indicated by the code CD.

[0035] The tampering detection unit 101 detects whether the inspection target document DB has been tampered with by determining the identity of the inspection target document DB and the registered document DC based on the document image GD and information about the registered document DC stored in the document database 91 in association with the identifier ID detected by the identifier detection unit 102. That is, the tampering detection unit 101 accesses the document database 91 via the communication unit 9, determines the identity of the document image GD and the registered document DC stored in the document database 91 in association with the identifier ID detected by the identifier detection unit 102, and detects that the inspection target document DB has been tampered with if it determines that there is no identity.

[0036] For example, the tampering detection unit 101 uses a known OCR (Optical Character Recognition) character recognition technology to recognize characters contained in the document image GD representing the document DB to be inspected, converts the document image GD into text, and compares the text of the document DB to be inspected with the converted registered document DC to determine whether they are identical.

[0037] The registered document DC is transcribed in advance, and the transcribed data is stored in the document database 91. Alternatively, if the registered document DC has not been transcribed in advance, the tampering detection unit 101 acquires the registered document DC via the communication unit 9, transcribs the registered document DC in the same manner as the document DB to be inspected, and then performs the identity determination.

[0038] Next, an example of copy job or scan transmission job control in image forming apparatus 1 will be described with reference to the flowchart shown in Fig. 5. This process is performed when operation unit 47 receives an instruction from a user to copy or scan and transmit a document (original).

[0039] When the operation unit 47 receives the above instruction from the user, the control unit 100 controls the operation of the document feed unit 6, document reading unit 5, etc., and causes the document reading unit 5 to read the document placed on the document placement tray 61 of the document feed unit 6 or on the platen glass (S1). The identifier detection unit 102 determines whether the document image GD obtained by document reading by the document reading unit 5 contains information indicating the identifier ID, that is, whether an image of the code CD (code CD indicating the identifier ID) is included in the document image GD (S4).

[0040] If the identifier detection unit 102 determines that the code CD (the code CD indicating the identifier ID) does not exist in the document image GD, i.e., that there is no information indicating the identifier ID (NO in S4), the control unit 100 causes the display unit 473 to display a message prompting the user to input an instruction as to whether or not to register the document indicated by the document image GD (a first-time document that does not include the code CD) in the document database 91 (S5).

[0041] When the control unit 100 receives an instruction from the user via the operation unit 47 indicating that the user does not wish to register the first-time document in the document database 91 (NO in S5), the control unit 100 executes a normal process (copy job or scan transmission job), i.e., a copy job or scan transmission job that does not include a process of combining an image showing the code CD with the document image GD obtained by document reading by the document reading unit 5 and a process of detecting tampering based on the code CD included in the document image GD (S3). Then, the process ends.

[0042] On the other hand, when the control unit 100 receives an instruction from the user at the operation unit 47 indicating that the user wishes to register the first-time document in the document database 91 (YES in S5), the control unit 100 causes the display unit 473 to display a message prompting the user to input the document name of the first-time document (the first-time document not including the code CD) indicated by the document image GD (S6).

[0043] When the operation unit 47 receives an input of the document name of a first-time document from the user, the control unit 100 creates an identifier ID unique to the first-time document to identify the first-time document (S7), and transmits information about the first-time document (an image showing the first-time document and its document name) linked to the created identifier ID to the document database 91 via the communication unit 9 (S8). The document database 91 stores the received identifier ID and information about the first-time document linked to the identifier ID. Next, the control unit 100 generates an image of a code CD indicating the identifier ID (S9), and combines the generated code CD with the document image GD of the first-time document (S10).

[0044] Next, the control unit 100 determines whether the user's instruction is to copy or scan and send (S11), and if the user's instruction is to copy ("Copy" in S11), the image forming unit 12 forms the document image GD generated by synthesizing the image of the code CD in S10 on a recording medium (S12). Then, the process ends. The inspection target document DB shown in FIG. 4(B) is an example of the processed document.

[0045] On the other hand, if the instruction from the user is to scan and send ("Send" in S11), the control unit 100 sends the document image GD generated by combining the image of the code CD in S10 to an external device (e.g., a personal computer) indicated by the instruction via the communication unit 9 (S13). Thereafter, the control unit 100 displays a message on the display unit 473 prompting the user to input an instruction to print the document image GD generated by combining the image of the code CD (S14).

[0046] When an instruction to print the document image GD generated by combining the image of the code CD is received from the operation unit 47 (YES in S14), the control unit 100 causes the image forming unit 12 to form the document image GD generated by combining the image of the code CD on the recording medium (S12). Then, the process ends.

[0047] Furthermore, in S4, if the identifier detection unit 102 determines that the identifier ID exists in the document indicated by the document image GD (YES in S4), the tampering detection unit 101 accesses the document database 91 via the communication unit 9 and acquires information about the registered document DC linked to the identifier ID detected by the identifier detection unit 102 from the document database 91 (S15).Then, the tampering detection unit 101 uses the acquired information about the registered document DC to determine whether the document image GD and the registered document DC are identical (S16), and if it determines that they are not identical, it detects that the inspection target document DB indicated by the document image GD has been tampered with (NO in S16).

[0048] If the tampering detection unit 101 detects that the inspection target document DB has been tampered with (NO in S16), the control unit 100 causes the display unit 473 to display a message indicating that the inspection target document DB has been tampered with (S19). Then, the process ends. In this case, since the inspection target document DB has been tampered with, the control unit 100 does not execute the copy operation or scan transmission.

[0049] If the tampering detection unit 101 detects that the above identity exists and that the document DB to be inspected has not been tampered with (YES in S16), the control unit 100 executes normal processing (copy job or scan transmission job), i.e., executes copy operation and scan transmission without restricting copy operation and scan transmission due to tampering detection (S18).Then, the processing ends.

[0050] In another embodiment, when the tampering detection unit 101 detects that the document DB to be inspected has not been tampered with (YES in S16), the control unit 100 may, for example, display a message on the display unit 473 prompting the user to input a continuation instruction to continue executing the job, and when the continuation instruction is accepted by the operation unit 47, the copy operation or scan transmission may be performed even if the document DB to be inspected has been tampered with.

[0051] According to the above embodiment, the documents to be checked for identity with the document DB to be inspected are determined based on the identifier ID indicated by the code CD added to the document DB to be inspected, which makes it easy to narrow down the documents to be checked, and enables efficient tamper detection, thereby improving the ability to detect tampering. Furthermore, since the text of the document DB to be inspected and the registered document are compared, the ability to detect tampering caused by the deletion or addition of characters from the original document is high.

[0052] In the above embodiment, the alteration detection unit 101 compares the text of the document DB to be inspected with that of the registered document DC to determine their identity. However, in another embodiment, instead of comparing the document DB to be inspected with the registered document DC using characters recognized by character recognition technology, the alteration detection unit 101 may determine the identity of the document image GD representing the document DB to be inspected and the image representing the registered document DC using a technique such as pattern matching. Alternatively, the alteration detection unit 101 may determine the identity of the document image GD and the image representing the registered document DC by comparing the characteristics of the images contained in the document DB to be inspected and the registered document DC. These characteristics include location, size, inclination, color, and saturation.

[0053] As shown in FIG. 4A, the registered document DC (original document DA) includes a mark M, which is a box around the character string "TOP SECRET." For example, as shown in FIG. 6, the characteristics of each character that makes up the mark M (the size, inclination, and saturation of the characters T, O, and P) may be registered in the document database 91 as information about the registered document DC, and the tampering detection unit 101 may determine the identity of the document image GD and the image representing the registered document DC based on this information. This makes it possible to detect tampering based on design discrepancies, etc. Note that, in the above-mentioned comparison of text and comparison by matching image characteristics, it is preferable to set a tolerance for error in determining identity.

[0054] Although it is not possible to detect whether a document to which a code CD is not added has been tampered with, a document to which a code CD has been added as described above is registered in the document database 91 as a registered document CD, and the document to which the code CD has been added is printed. This allows documents that originally did not have a code CD added and were not subject to tampering detection to be subject to tampering detection.

[0055] The present invention is not limited to the configuration of the above embodiment, and various modifications are possible. In addition, in the above embodiment, the configuration and processing shown in the above embodiment using Figures 1 to 6 are merely one embodiment of the present invention, and it is not intended that the present invention be limited to these configurations and processing. [Explanation of symbols]

[0056] 1. Image forming device 5 Document reading section 12 Image forming unit 91 Document Database 100 control section 101 Tampering detection unit 102 Identifier detection unit

Claims

1. a document reading unit that reads an image of a document to be inspected; an identifier detection unit that detects an identifier indicated by a code included in the document to be inspected, based on a document image indicating the document to be inspected obtained by reading by the document reading unit; A tampering detection device comprising: a tampering detection unit that accesses a document database that stores information about registered documents linked to a unique identifier, determines the identity of the document image with the registered document stored in the document database linked to the identifier detected by the identifier detection unit, and detects that the document to be inspected has been tampered with when it determines that there is no identity.

2. 2. The tampering detection device according to claim 1, wherein the tampering detection unit recognizes characters contained in the document image, determines whether the recognized character group contained in the document image is identical to the character group contained in the registered document, and, if it determines that there is no identity, determines that there is no identity between the document image and the registered document.

3. the falsification detection unit determines whether features of images included in the document image and the registered document are identical, and when determining that there is no identity, determines that there is no identity between the document image and the registered document; The tamper detection device according to claim 1 , wherein the features include at least one of location, size, inclination, color, and saturation.

4. 2. The tampering detection device of claim 1, further comprising a control unit that, when the identifier detection unit does not detect the identifier from the document to be inspected, creates a unique identifier for the document to be inspected and a code indicating the identifier, and stores the identifier and a document image indicating the document to be inspected in the document database.

5. The tamper detection device according to claim 4; an image forming unit that forms an image on a recording medium; When the identifier is not detected from the document to be inspected by the identifier detection unit, the control unit combines a code indicating the created identifier with a document image indicating the document to be inspected, and causes the image forming unit to form the combined document image on the recording medium.

Images