Display control system, display control method, and program

Abstract

To provide a new technology for preventing information displayed on a display screen from leaking.SOLUTION: A display control device includes: a detection unit that uses image data in which the periphery of a display device is included to detect a situation in which object information displayed by the display device can be browsed by a person other than a specific person; and a state change unit that depending on detection of the situation, changes an output state of the object information at the display device. The display device displays screen data transmitted via a network. Processing of changing the output state of the object information is processing of intercepting transmission of the screen data at a device of a transmission source of the screen data.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a technique for preventing information leakage.

Background Art

[0002] Some information handled in work or the like is restricted to those who are permitted to view it. For example, information that can only be viewed by people within the same company or group. When handling such information where the number of people permitted to view it is restricted, it is necessary to prevent unauthorized people from seeing the information and thus prevent information leakage.

[0003] Therefore, systems have been developed to prevent unauthorized people from seeing information. For example, Patent Document 1 discloses a technique that uses a camera to determine whether the user of an electronic device is a person with usage permission, and controls the display on the display screen according to the determination. More specifically, the electronic device in Patent Document 1 compares the face image of the user of the electronic device obtained from the camera with the face images of people with usage permission to determine whether the user has usage permission. If it is detected that the user does not have usage permission and that the user's line of sight is directed at the display screen, the visibility of the image displayed on the display screen is deteriorated.

[0004] Patent Document 2 discloses a technique for changing the display on the display screen to an illegible state when a person other than the operator is detected by a human presence sensor. The human presence sensor is provided to detect people within a predetermined range around the display screen and where the operator is not present.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] The situation where the information displayed on the display screen leaks is not limited to the situation where a person without the right to use takes an image with a camera that images the periphery of the display screen, or the situation where a person other than the operator is detected by a human sensor that detects a person around the display screen.

[0007] The present invention has been made in view of the above problems, and one of its objects is to provide a new technology for preventing the leakage of information displayed on the display screen.

Means for Solving the Problems

[0008] The first display control system of the present disclosure includes a detection means for detecting a camera capable of imaging the screen of the display device from image data including the periphery of the display device, and a control means for darkening the screen of the display device when the camera is detected. The second display control system of the present disclosure includes a detection means for detecting a camera capable of imaging the screen of the display device from image data including the periphery of the display device, and a control means for blocking the screen data transmitted to the display device when the camera is detected. The third display control system of the present disclosure includes an imaging means provided in the display device for imaging a person operating a computer, a detection means for detecting a camera from the image data imaged by the imaging means, and a control means for darkening the screen of the display device when the camera is detected. The fourth display control system of the present disclosure includes an imaging means provided in the display device for imaging a person operating a computer, a detection means for detecting a camera from the image data imaged by the imaging means, and a control means for blocking the screen data transmitted to the display device when the camera is detected.

[0009] The first display control method of the present disclosure is executed by a computer, and when the screen of the display device is about to be photographed by a camera, the screen of the display device is darkened. The second display control method of the present disclosure is executed by a computer, and when the screen of the display device is about to be photographed by a camera, the screen data transmitted to the display device is blocked.

[0010] The first program of the present disclosure causes a computer to execute a process of darkening the screen of the display device when the screen of the display device is about to be photographed by a camera. The second program of the present disclosure causes a computer to execute a process of blocking the screen data transmitted to the display device when the screen of the display device is about to be photographed by a camera.

Advantages of the Invention

[0011] According to the present invention, a new technology for preventing leakage of information displayed on the display screen is provided.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In each drawing, the same or corresponding elements are denoted by the same reference numerals, and redundant descriptions are omitted as necessary for clarity of explanation.

[0014] FIG. 1 is a diagram illustrating an overview of the display control device (the display control device 2000 in FIG. 2 described later) according to Embodiment 1. Note that the following description with reference to FIG. 1 is for facilitating the understanding of the display control device 2000 according to Embodiment 1, and the operation of the display control device 2000 according to Embodiment 1 is not limited to that described below.

[0015] The display control device 2000 controls the display of information by the display device 10. Hereinafter, the information whose display is controlled by the display control device 2000 is referred to as target information. The target information may be all the information displayed on the display device 10 or may be some of the information. The target information is information that should be avoided from being viewed by persons other than those permitted to view it. For example, information that is only permitted to be viewed by employees or information that is only permitted to be viewed by a specific group.

[0016] The display control device 2000 detects that 1) the target information displayed on the display device 10 is in a first situation where there is a risk of being viewed by a person other than the specific person 30, or 2) the target information displayed on the display device 10 is in a second situation where there is a risk of being imaged by a camera. Note that the display control device 2000 may be configured to detect only one of these two situations or may be configured to detect both. Hereinafter, the first situation and the second situation are collectively referred to as the "predetermined situation". Note that a plurality of specific persons 30 may be defined.

[0017] The detection of the first situation and the second situation is performed using the sensor data obtained from the sensor 20. The sensor 20 is provided so as to obtain data regarding the situation around the display device 10 as sensor data. For example, the sensor 20 is a camera, a microphone, or the like. When the sensor 20 is a camera, the sensor data is image data or video data. When the sensor 20 is a microphone, the sensor data is audio data.

[0018] When the first situation or the second situation is detected using the sensor data, the display control device 2000 performs control so that the output state of the target information by the display device 10 is changed. The change in the output state is a process of making the target information unviewable or a process of making the target information difficult to view. The former is, for example, a process of stopping the display of information by the display device 10. The latter is, for example, a process of dimming the brightness of the display of the display device 10 or adding processing to the display.

[0019] For example, in Case 1 of FIG. 1, the first situation is detected because a person other than the specific person 30 appears at a position where the display device 10 can be viewed. As a result, no information is displayed on the display device 10. In Case 2 of FIG. 1, the second situation is detected because the specific person 30 attempts to image the information displayed on the display device 10 with the camera of the smartphone. As a result, a control process of superimposing a dot pattern on the information displayed on the display device 10 is being performed.

[0020] Note that in FIG. 1, for the purpose of showing variations in the display control, the display control is different when the first situation is detected and when the second situation is detected. However, the display control may be the same when the first situation is detected and when the second situation is detected.

[0021] Thus, according to the display control device 2000 of the present embodiment, when 1) a situation where the target information displayed on the display device 10 may be viewed by a person other than the specific person 30, or 2) a situation where the target information displayed on the display device 10 may be captured by a camera is detected, in response to the detection, the target information displayed on the display device 10 can be made unviewable or the visibility of the target information can be reduced. Thereby, leakage of the target information displayed on the display device 10 can be prevented.

[0022] Hereinafter, the display control device 2000 of the present embodiment will be described in more detail.

[0023] <Example of functional configuration> FIG. 2 is a block diagram illustrating the functional configuration of the display control device 2000. The display control device 2000 includes a detection unit 2020 and a state change unit 2040. The detection unit 2020 uses the sensor data obtained from the sensor 20 to detect whether the target information displayed by the display device 10 is in a predetermined situation (the first situation or the second situation). The state change unit 2040 performs control so that the output state of the target information in the display device 10 is changed in response to the detection. The changed output state is a state where the target information is not displayed or a state where the visibility of the target information is lower than before the change.

[0024] <Example of hardware configuration> Each functional component of the display control device 2000 may be realized by hardware (e.g., a hard-wired electronic circuit, etc.) that realizes each functional component, or may be realized by a combination of hardware and software (e.g., a combination of an electronic circuit and a program that controls it, etc.). Hereinafter, the case where each functional component of the display control device 2000 is realized by a combination of hardware and software will be further described.

[0025] FIG. 3 is a block diagram illustrating the hardware configuration of a computer 500 that realizes the display control device 2000. The computer 500 is an arbitrary computer. For example, the computer 500 is a stationary computer such as a PC (Personal Computer) or a server machine. In addition, for example, the computer 500 is a portable computer such as a smartphone or a tablet terminal. In addition, for example, the computer 500 may be a controller built into the display device 10. The computer 500 may be a dedicated computer designed to realize the display control device 2000, or may be a general-purpose computer.

[0026] For example, by installing a predetermined application on the computer 500, each function of the display control device 2000 is realized on the computer 500. The above application is composed of a program for realizing the functional components of the display control device 2000.

[0027] The computer 500 includes a bus 502, a processor 504, a memory 506, a storage device 508, an input / output interface 510, and a network interface 512. The bus 502 is a data transmission path for the processor 504, the memory 506, the storage device 508, the input / output interface 510, and the network interface 512 to transmit and receive data to and from each other. However, the method of connecting the processor 504 and the like to each other is not limited to bus connection.

[0028] The processor 504 is various processors such as a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), or an FPGA (Field-Programmable Gate Array). The memory 506 is a main storage device realized using, for example, RAM (Random Access Memory). The storage device 508 is an auxiliary storage device realized using a hard disk, an SSD (Solid State Drive), a memory card, or a ROM (Read Only Memory).

[0029] The input / output interface 510 is an interface for connecting the computer 500 and an input / output device. For example, an input device such as a keyboard and an output device such as a display device are connected to the input / output interface 510.

[0030] The network interface 512 is an interface for connecting the computer 500 to a network. This network may be a LAN (Local Area Network) or a WAN (Wide Area Network).

[0031] The storage device 508 stores a program (a program that realizes the aforementioned application) that realizes each functional component of the display control device 2000. The processor 504 reads out and executes this program in the memory 506, thereby realizing each functional component of the display control device 2000.

[0032] The display control device 2000 may be realized by one computer 500 or by a plurality of computers 500. In the latter case, the configurations of the respective computers 500 do not have to be the same and may be different from each other.

[0033] <Flow of processing> FIG. 4 is a flowchart illustrating the flow of processing executed by the display control device 2000 according to Embodiment 1. The detection unit 2020 acquires sensor data of the sensor 20 (S102). The detection unit 2020 determines whether a predetermined situation has occurred by using the sensor data (S104). When it is determined that a predetermined situation has occurred (S104: YES), the state change unit 2040 executes control processing so that the output state of the target information in the display device 10 is changed (S106).

[0034] <Detection of Predetermined Situation> The detection unit 2020 determines whether a predetermined situation has occurred by using the sensor data obtained from the sensor 20. As described above, the predetermined situation is the first situation (a situation where there is a risk that the target information displayed on the display device 10 may be viewed by a person other than the specific person 30) or the second situation (a situation where there is a risk that the target information displayed on the display device 10 may be captured by a camera). Hereinafter, the detection method for each of the first situation and the second situation will be exemplified.

[0035] <<Method for Detecting the First Situation>> The detection of the first situation can be realized by detecting the presence of a person other than the specific person 30 by using the sensor data obtained from the sensor 20. This will be specifically described below.

[0036] <<<Case of Using a Camera>>> For example, assume that the sensor 20 uses a camera provided to image the periphery of the display device 10. In this case, the detection unit 2020 acquires, as sensor data, the image data generated by the camera. Note that various existing methods can be adopted for the method of acquiring image data from the camera.

[0037] The camera is provided so that the area where the display device 10 can be viewed is included in the imaging range. The camera may be built into the display device 10 or may be installed around the display device 10.

[0038] Note that the image data mentioned here also includes video frames that make up video data. That is, the sensor data may be still image data generated by a still camera or video data generated by a video camera. Further, the camera is not limited to one that captures visible light and may be one that captures invisible light (for example, an infrared camera).

[0039] For example, when the number of people included in the image data is greater than a predetermined threshold (for example, 1), the detection unit 2020 determines that the first situation has occurred. In this case, the detection unit 2020 determines whether the number of people included in the image data is greater than the threshold. When the number of people included in the image data is greater than the threshold, the detection unit 2020 determines that the first situation has occurred. On the other hand, when the number of people included in the image data is less than or equal to the threshold, the detection unit 2020 determines that the first situation has not occurred.

[0040] In addition, for example, when the image data obtained from the camera includes people other than the specific person 30, the detection unit 2020 determines that the first situation has occurred. In this case, the detection unit 2020 calculates feature amounts on the image (hereinafter referred to as image feature amounts) for one or more people included in the image data. The detection unit 2020 compares the image feature amounts of each person included in the image data with the image feature amounts of the specific person 30 stored in a storage device that can be accessed by the detection unit 2020 in advance. When the image feature amounts of the people detected from the image data include those that do not match the image feature amounts of the specific person 30 (for example, those with a similarity less than the threshold), the detection unit 2020 determines that the first situation has occurred. On the other hand, when all of the image feature amounts of the people detected from the image data match the image feature amounts of the specific person 30 (for example, the similarity is greater than or equal to the threshold), the detection unit 2020 determines that the first situation has not occurred.

[0041] <<<Case of using a microphone>>> A case where a microphone is used as the sensor 20 will be described. In this case, the sensor data is audio data. The microphone is provided to detect the sound around the display device 10. In particular, the microphone is preferably provided to detect the sound coming from the direction where the person viewing the display device 10 is located (in front of the display screen of the display device 10). Note that various existing methods can be adopted as the method for acquiring audio data from the microphone.

[0042] For example, when the number of people whose voices are included in the audio data is greater than a predetermined threshold (for example, 1), the detection unit 2020 determines that the first situation has occurred. In this case, the detection unit 2020 analyzes the audio data obtained from the microphone, calculates the number of people whose voices are included in the audio data, and compares it with the threshold. When the number of people whose voices are included in the audio data is greater than the threshold, the detection unit 2020 determines that the first situation has occurred. On the other hand, when the number of people whose voices are included in the audio data is less than or equal to the threshold, the detection unit 2020 determines that the first situation has not occurred.

[0043] In addition, for example, when the voices of people other than the specific person 30 are included in the audio data, the detection unit 2020 determines that the first situation has occurred. In this case, the detection unit 2020 calculates the voice feature amount (hereinafter referred to as the voice feature amount) for each person's voice included in the audio data. The detection unit 2020 compares the voice feature amount of each person's voice detected from the audio data with the voice feature amount of the voice of the specific person 30 stored in a storage device that can be accessed by the detection unit 2020 in advance. When there is a voice feature amount among the voice feature amounts of each person's voice included in the audio data that does not match the voice feature amount of the voice of the specific person 30 (for example, the similarity is less than the threshold), the detection unit 2020 determines that the first situation has occurred. On the other hand, when the voice feature amounts of each person's voice included in the audio data all match the voice feature amount of the voice of the specific person 30 (for example, the similarity is greater than or equal to the threshold), the detection unit 2020 determines that the first situation has not occurred.

[0044] <<Method for Detecting the Second Situation>> The detection of the second situation can be realized by using the sensor data obtained from the sensor 20 to detect the presence of cameras other than the camera provided as the sensor 20. For example, assume that a camera is used as the sensor 20. In this case, if the detection unit 2020 determines that the image data obtained as the sensor data contains a specific type of object that can capture the display screen of the display device 10, it is determined that the second situation has occurred. The specific type of object is a camera or an object where a camera may be provided (for example, a mobile terminal such as a smartphone or a tablet terminal). In this case, the image feature amount of the specific type of object is stored in a storage device accessible from the detection unit 2020.

[0045] The detection unit 2020 determines whether the image feature amount of the specific type of object is included in the image data obtained from the camera provided as the sensor 20. If it is determined that the image feature amount of the specific type of object is included, the detection unit 2020 determines that the second situation has occurred. On the other hand, if it is determined that the image feature amount of the specific type of object is not included, the detection unit 2020 determines that the second situation has not occurred.

[0046] <Switching of the specific person 30> The specific person 30 may be different for each target information. For example, for the target information named File A, it is conceivable that the user U1 is set as the specific person 30, and for the target information named File B, the user U2 is set as the specific person 30. In this case, a pair of the identification information of the target information and the identification information of the specific person 30 (for example, the image feature amount of the specific person 30 described above or the voice feature amount of the voice of the specific person 30) is stored in advance in a storage device accessible from the detection unit 2020. The detection unit 2020 acquires the identification information of the target information displayed on the display device 10, acquires the identification information of the specific person 30 associated with the identification information, and uses the acquired identification information of the specific person 30 to detect a predetermined situation.

[0047] <Timing when the detection of the predetermined situation is performed> The detection unit 2020 may repeatedly detect a predetermined situation at all times (for example, perform detection processing at predetermined time intervals), or may detect a predetermined situation only when a predetermined condition is satisfied. For example, assume that the target information is limited to some information rather than all information. In this case, the detection unit 2020 performs a process of detecting a predetermined situation only when the target information is being displayed on the display device 10. In this case, the identification information of each piece of information (for example, a file) to be treated as target information is stored in advance in a storage device accessible from the detection unit 2020. At the timing of detecting a predetermined situation, the detection unit 2020 acquires the identification information of each piece of information being displayed on the display device 10, and determines whether the identification information of the target information is included therein. If the identification information of the target information is included, the detection unit 2020 detects a predetermined situation. On the other hand, if the identification information of the target information is not included, the detection unit 2020 does not detect a predetermined situation.

[0048] Further, while the detection unit 2020 repeatedly detects a predetermined situation at all times, a condition that "the target information is being displayed on the display device 10" may be added to the condition for detecting a predetermined situation. For example, the detection unit 2020 determines that the first situation has occurred when a condition that "the target information is being displayed on the display device 10 and, in addition, the image data obtained from the camera includes a person other than the specific person 30" is satisfied.

[0049] <Change in output state> When a predetermined situation is detected, the state change unit 2040 performs control processing so that the output state of the target information on the display device 10 is changed. For example, the state change unit 2040 performs control processing so that not all information is output from the display device 10. By doing so, since all the information that was being displayed on the display device 10 becomes unviewable, a person other than the specific person 30 cannot view the target information. Also, it becomes impossible to capture the target information with the camera. Such control processing is, for example, a process of turning off the power of the display device 10 or blocking the transmission of screen data to the display device 10.

[0050] For example, the state change unit 2040 also performs control processing so that the visibility of the information output from the display device 10 is reduced. By doing so, even if a person other than the specific person 30 views the target information, it is possible to make it difficult to understand the content. Similarly, even if the target information is imaged by a camera, it is possible to make it difficult to understand the content of the imaged information.

[0051] The control processing for reducing the visibility of information is, for example, processing for reducing the brightness of the display device 10 or processing for processing the screen data displayed on the display device 10. The processing to be added to the screen data is, for example, processing for changing the color tone of the screen data (changing it to a dark color overall), processing for superimposing other image data (dot pattern, etc.) on the screen data, or processing for changing the screen data according to a predetermined algorithm (applying a mosaic, etc.).

[0052] Note that when the target information is only a part of the information (for example, one of a plurality of files displayed on the display device 10), the state change unit 2040 may change the output state only for the target information. Such processing is, for example, processing for minimizing the window of the target information or processing for making the window transparent (setting the opacity to zero). Also, the processing to be added to the above-described screen data may be added only to the window of the target information.

[0053] The targets to which the state change unit 2040 applies control for the above-described control process are various. For example, the state change unit 2040 controls the hardware of the display device 10. For example, by turning off the power of the display device 10, information can be prevented from being displayed on the display device 10, or by reducing the brightness of the display device 10, the visibility of the information displayed on the display device 10 can be reduced. In addition, for example, the state change unit 2040 may control a machine (for example, a PC operated by a specific person 30) that is connected to the display device 10 and outputs screen data to the display device 10. For example, a process of blocking the output of screen data to the display device 10 or processing the screen data can be performed by a program (for example, a device driver) in an operating system operating on the machine that outputs the screen data.

[0054] In addition, for example, when the target information is data provided via a network, the state change unit 2040 may control the communication via the network. FIG. 5 is a diagram illustrating a case where target information is provided via a network. In FIG. 5, the target information is a file in the company-side machine 110. The specific person 30 remotely connects to the company-side machine 110 from the home-side machine 100 via a VPN (virtual private network). The VPN connection is realized by a company-side VPN device 120 installed in the company and a home-side VPN device 130 installed in the home of the specific person 30.

[0055] In this case, the screen data generated by the company-side machine 110 is transmitted to the home-side machine 100 via the company-side VPN device 120 and the home-side VPN device 130. Then, the screen data is output from the home-side machine 100 to the display device 10. Therefore, by blocking the transmission of the screen data or adding processing to the screen data in any of the company-side machine 110, the company-side VPN device 120, or the home-side VPN device 130, the above-described control process can be realized.

[0056] For example, in this case, the company-side machine 110, the company-side VPN device 120, or the home-side VPN device 130 functions as the display control device 2000. In this case, sensor data is transmitted from the sensor 20 to these devices.

[0057] Alternatively, the function of the detection unit 2020 may be provided in the home-side machine 100, and the function of the state change unit 2040 may be provided in the company-side machine 110, the company-side VPN device 120, or the home-side VPN device 130. In this case, the home-side machine 100 detects a predetermined situation and notifies the device provided with the function of the state change unit 2040 that the predetermined situation has been detected. Then, in the device that has received the notification, a process of controlling the display is performed.

[0058] As described above, the present invention has been described with reference to the embodiments, but the present invention is not limited to the above embodiments. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention.

[0059] In the above example, the program can be stored using various types of non-transitory computer readable media and provided to a computer. The non-transitory computer readable media include various types of tangible storage media. Examples of non-transitory computer readable media include magnetic recording media (e.g., flexible disks, magnetic tapes, hard disk drives), magneto-optical recording media (e.g., magneto-optical disks), CD-ROM, CD-R, CD-R / W, semiconductor memories (e.g., mask ROM, PROM (Programmable ROM), EPROM (Erasable PROM), flash ROM, RAM). Also, the program may be provided to the computer by various types of transitory computer readable media. Examples of transitory computer readable media include electrical signals, optical signals, and electromagnetic waves. The transitory computer readable media can supply the program to the computer via wired communication channels such as electric wires and optical fibers, or wireless communication channels.

[0060] Some or all of the above embodiments may also be described as follows, but are not limited thereto. (Appendix 1) A detection unit that detects a first situation in which target information displayed by the display device can be viewed by a person other than a specific person using audio data including sounds around the display device, or detects a second situation in which the target information displayed by the display device can be imaged by a camera using image data included in the surroundings of the display device; A state change unit that changes an output state of the target information in the display device in response to detection of the first situation or the second situation; and A display control device, wherein the change of the output state is a process of stopping the output of the target information or a process of reducing the visibility of the target information compared to before the change. (Appendix 2) When the detection unit detects the voices of a number of people equal to or greater than a predetermined threshold from the voice data, or when the detection unit detects a voice having a voice feature amount that does not match the voice feature amount of the specific person from the voice data, the display control device according to Supplementary Note 1 determines that the first situation has occurred. (Supplementary Note 3) The detection unit acquires the voice feature amount of the specific person corresponding to the target information displayed on the display device from a storage device that stores a plurality of associations between the target information and the voice feature amount of the specific person, and when the voice data includes a voice feature amount that does not match the acquired voice feature amount of the specific person, the display control device according to Supplementary Note 2 detects the first situation. (Supplementary Note 4) When the detection unit detects an image feature amount of a specific type of object that can capture the target information displayed on the display device from the image data, the display control device according to Supplementary Note 1 determines that the second situation has occurred. (Supplementary Note 5) The detection unit according to any one of Supplementary Notes 1 to 4 detects the first situation or the second situation only when the target information is displayed on the display device. (Supplementary Note 6) The process of reducing the visibility of the target information is a process of reducing the luminance of the display device or a process of processing the screen data output to the display device, and is the display control device according to any one of Supplementary Notes 1 to 5. (Supplementary Note 7) The display device displays screen data transmitted via a network, and the state change unit blocks the transmission of the screen data or processes the screen data in the device that is the transmission source of the screen data or the device that relays the transmission of the screen data by that device, and is the display control device according to any one of Supplementary Notes 1 to 6. (Supplementary Note 8) The display control device is provided inside the display device, and is the display control device according to any one of Appendices 1 to 7. (Appendix 9) A display control method executed by a computer, comprising: using audio data including sounds around the display device to detect a first situation in which target information displayed by the display device can be viewed by a person other than a specific person, or using image data included in the surroundings of the display device, detecting a second situation in which the target information displayed by the display device can be imaged by a camera; a detection step; a state change step of changing an output state of the target information in the display device in response to detection of the first situation or the second situation; The change in the output state is a process of stopping the output of the target information or a process of reducing the visibility of the target information compared to before the change. A display control method. (Appendix 10) In the detection step, when a voice of a number of people equal to or greater than a predetermined threshold is detected from the audio data, or when a voice having a voice feature amount that does not match the voice feature amount of the specific person's voice is detected from the audio data, it is determined that the first situation is occurring. The display control method according to Appendix 9. (Appendix 11) In the detection step, acquiring the voice feature amount of the specific person corresponding to the target information displayed on the display device from a storage device that stores a plurality of associations between the target information and the voice feature amounts of the specific person; The display control method according to Appendix 10, wherein when the audio data includes a voice feature amount that does not match the acquired voice feature amount of the specific person, the first situation is detected. (Appendix 12) In the detection step, when an image feature amount of a specific type of object capable of imaging the target information displayed on the display device is detected from the image data, it is determined that the second situation is occurring. The display control method according to Appendix 9. (Appendix 13) The display control method according to any one of Appendices 9 to 12, wherein in the detection step, the detection of the first situation or the second situation is performed only when the target information is being displayed on the display device. (Appendix 14) The process of reducing the visibility of the target information is a process of reducing the brightness of the display device or a process of processing the screen data output to the display device. The display control method according to any one of Appendices 9 to 13. (Appendix 15) The display device is displaying screen data transmitted via a network. In the state change step, in the device that is the transmission source of the screen data or the device that relays the transmission of the screen data by that device, the process is to cut off the transmission of the screen data or to process the screen data. The display control method according to any one of Appendices 9 to 14. (Appendix 16) The computer is provided inside the display device. The display control method according to any one of Appendices 9 to 15. (Appendix 17) A computer-readable medium storing a program, wherein the program causes the computer to perform a detection step of detecting, using audio data including sounds around the display device, a first situation in which the target information displayed by the display device can be viewed by a person other than a specific person, or detecting, using image data included in the surroundings of the display device, a second situation in which the target information displayed by the display device can be captured by a camera; and a state change step of changing an output state of the target information in the display device in response to the detection of the first situation or the second situation, wherein the change of the output state is a process of stopping the output of the target information or a process of reducing the visibility of the target information compared to before the change. A computer-readable medium. (Appendix 18) In the detection step, when a voice of a number of people equal to or greater than a predetermined threshold is detected from the voice data, or when a voice having a voice feature amount that does not match the voice feature amount of the specific person is detected from the voice data, it is determined that the first situation has occurred. The computer-readable medium according to Appendix 17. (Appendix 19) In the detection step, from a storage device that stores a plurality of associations between the target information and the voice feature amounts of the specific person, the voice feature amount of the specific person corresponding to the target information displayed on the display device is acquired, The computer-readable medium according to Appendix 18, wherein when the voice data includes a voice feature amount that does not match the acquired voice feature amount of the specific person, the first situation is detected. (Appendix 20) In the detection step, when an image feature amount of a specific type of object capable of imaging the target information displayed on the display device is detected from the image data, it is determined that the second situation has occurred. The computer-readable medium according to Appendix 17. (Appendix 21) In the detection step, the detection of the first situation or the second situation is performed only when the target information is displayed on the display device. The computer-readable medium according to any one of Appendices 17 to 20. (Appendix 22) The process of reducing the visibility of the target information is a process of reducing the brightness of the display device or a process of processing the screen data output to the display device. The computer-readable medium according to any one of Appendices 17 to 21. (Appendix 23) The display device displays screen data transmitted via a network, In the state change step, in the device that is the transmission source of the screen data or the device that relays the transmission of the screen data by that device, a computer-readable medium according to any one of Appendices 17 to 22, which is a process of blocking the transmission of the screen data or processing the screen data. (Appendix 24) The computer is provided inside the display device, a computer-readable medium according to any one of Appendices 17 to 23.

Explanation of Signs

[0061] 10 Display device 20 Sensor 30 Specific person 100 Home-side machine 110 Company-side machine 120 Device 130 Device 500 Computer 502 Bus 504 Processor 506 Memory 508 Storage device 510 Input / output interface 512 Network interface 2000 Display control device 2020 Detection unit 2040 State change unit

Claims

1. A detection means for detecting a camera capable of capturing an image of a screen of the display device from image data including the surroundings of the display device; and control means for dimming a screen of the display device when the camera is detected.

2. A detection means for detecting a camera capable of capturing an image of a screen of the display device from image data including the surroundings of the display device; and control means for blocking screen data being transmitted to the display device when the camera is detected.

3. An imaging means provided in the display device for imaging a person operating the computer; a detection means for detecting a camera from image data captured by the imaging means; and control means for dimming a screen of the display device when the camera is detected.

4. An imaging means provided in the display device for imaging a person operating the computer; a detection means for detecting a camera from image data captured by the imaging means; and control means for blocking screen data being transmitted to the display device when the camera is detected.

5. 11. A computer-implemented display control method for dimming a screen of a display device when the screen of the display device is about to be photographed by a camera.

6. A computer-implemented display control method for blocking screen data being sent to a display device when the screen of the display device is about to be photographed by a camera.

7. A program that causes a computer to execute a process of darkening a screen of a display device when the screen of the display device is about to be photographed by a camera.

8. A program that causes a computer to execute a process of blocking screen data transmitted to a display device when the screen of the display device is about to be photographed by a camera.

Images