DISPLAY CONTROL DEVICE, DISPLAY CONTROL METHOD, AND PROGRAM

Abstract

To provide display control devices, methods, and programs for preventing leakage of information displayed on display screens.SOLUTION: A display control device includes: a detection unit configured to use image data including surroundings of a display device 10 to detect a situation in which object information displayed by the display device may be viewed by people other than a specific person; and a state change unit configured to change an output state of the object information on the display device in response to detection of the situation. The display device displays screen data transmitted via a network. The processing of changing the output state of the object information is processing of blocking transmission of the screen data in a transmission source device of the screen data.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] Some information handled at work, etc., is only accessible to a limited number of people. For example, it may be information that can only be viewed by people within the same company or group. When handling information that is only accessible to a limited number of people, it is necessary to prevent information leakage by preventing unauthorized people from viewing the information.

[0003] Therefore, a system has been developed to prevent information from being seen by a person who is not authorized to view it. For example, Patent Document 1 discloses a technology that uses a camera to determine whether or not the user of an electronic device is a person authorized to use the electronic device, and controls the display on the display screen according to the determination. More specifically, the electronic device of Patent Document 1 determines whether or not the user is authorized to use the electronic device by comparing a facial image of the user of the electronic device obtained from the camera with a facial image of a person authorized to use the electronic device. Then, if it is detected that the user is not authorized to use the electronic device and that the user's gaze is directed toward the display screen, the visibility of the image displayed on the display screen is reduced.

[0004] Patent Document 2 discloses a technology that changes the display on the display screen to an unreadable 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, where the operator is not present. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2018 / 084835 [Patent Document 2] JP 2010-122754 A Summary of the Invention [Problem to be solved by the invention]

[0006] Situations in which information displayed on the display screen may be leaked are not limited to situations in which a person without permission to use the screen is captured by a camera capturing images of the area around the display screen, or situations in which a person other than the operator is detected by a human presence sensor that detects people around the display screen.

[0007] The present invention has been made in view of the above-mentioned problems, and one of the objects thereof is to provide a new technique for preventing leakage of information displayed on a display screen. [Means for solving the problem]

[0008] A first display control device of the present disclosure includes a detection unit that detects a situation in which target information displayed by a display device may be viewed by a person other than a specific person using image data including the surroundings of the display device, and a state change unit that changes an output state of the target information on the display device in response to the detection of the situation. The display device displays screen data transmitted via a network. The process of changing the output state of the target information is a process of blocking transmission of the screen data in a device that is a transmission source of the screen data. A second display control device of the present disclosure includes a detection unit that detects a situation in which target information displayed by a display device may be viewed by a person other than a specific person using image data including the surroundings of the display device, and a state change unit that changes an output state of the target information on the display device in response to the detection of the situation. The display device displays screen data transmitted via a network. The process of changing the output state of the target information is a process of processing the screen data in a device that is a transmission source of the screen data. A third display control device of the present disclosure includes a detection unit that detects a situation in which target information displayed by a display device may be viewed by a person other than a specific person by using image data including the surroundings of the display device, and a state change unit that changes an output state of the target information on the display device in response to the detection of the situation. The display device displays screen data transmitted via a network. The process of changing the output state of the target information is a process of blocking transmission of the screen data in a relay device that relays transmission of the screen data transmitted from a device that is a transmission source of the screen data. A fourth display control device of the present disclosure includes a detection unit that detects a situation in which target information displayed by a display device may be viewed by a person other than a specific person by using image data including the surroundings of the display device, and a state change unit that changes an output state of the target information on the display device in response to the detection of the situation. The display device displays screen data transmitted via a network. The process of changing the output state of the target information is a process of processing the screen data in a relay device that relays the transmission of the screen data transmitted from a device that is a source of the screen data.

[0009] The first display control method of the present disclosure includes a detection step executed by a computer, which detects a situation in which target information displayed by a display device may be viewed by a person other than a specific person using image data including the surroundings of the display device, and a state change step of changing an output state of the target information on the display device in response to the detection of the situation. The display device displays screen data transmitted via a network. The process of changing the output state of the target information is a process of blocking transmission of the screen data in a device that is a transmission source of the screen data. A second display control method of the present disclosure includes a detection step executed by a computer, which detects a situation in which target information displayed by a display device may be viewed by a person other than a specific person using image data including the surroundings of the display device, and a state change step of changing an output state of the target information on the display device in response to the detection of the situation. The display device displays screen data transmitted via a network. The process of changing the output state of the target information is a process of processing the screen data in a device that is a source of the screen data. A third display control method of the present disclosure includes a detection step, which is executed by a computer, and detects a situation in which target information displayed by a display device may be viewed by a person other than a specific person using image data including the surroundings of the display device, and a state change step, which changes an output state of the target information on the display device in response to the detection of the situation. The display device displays screen data transmitted via a network. The process of changing the output state of the target information is a process of blocking transmission of the screen data in a relay device that relays transmission of the screen data transmitted from a device that is a source of the screen data. A fourth display control method of the present disclosure includes a detection step executed by a computer, which detects a situation in which target information displayed by a display device may be viewed by a person other than a specific person using image data including the surroundings of the display device, and a state change step of changing an output state of the target information on the display device in response to the detection of the situation. The display device displays screen data transmitted via a network. The process of changing the output state of the target information is a process of processing the screen data in a relay device that relays the transmission of the screen data transmitted from a device that is a source of the screen data.

[0010] A first program of the present disclosure causes a computer to execute a detection step of detecting a situation in which target information displayed by a display device may be viewed by a person other than a specific person using image data including the surroundings of the display device, and a state change step of changing an output state of the target information on the display device in response to the detection of the situation. The display device displays screen data transmitted via a network. The process of changing the output state of the target information is a process of blocking transmission of the screen data in a device that is a transmission source of the screen data. A second program of the present disclosure causes a computer to execute a detection step of detecting a situation in which target information displayed by a display device may be viewed by a person other than a specific person using image data including the surroundings of the display device, and a state change step of changing an output state of the target information on the display device in response to the detection of the situation. The display device displays screen data transmitted via a network. The process of changing the output state of the target information is a process of processing the screen data in a device that is a source of the screen data. A third program of the present disclosure causes a computer to execute a detection step of detecting a situation in which target information displayed by a display device may be viewed by a person other than a specific person using image data including the surroundings of the display device, and a state change step of changing an output state of the target information on the display device in response to the detection of the situation. The display device displays screen data transmitted via a network. The process of changing the output state of the target information is a process of blocking transmission of the screen data in a relay device that relays transmission of the screen data transmitted from a device that is a transmission source of the screen data. A fourth program of the present disclosure causes a computer to execute a detection step of detecting a situation in which target information displayed by a display device may be viewed by a person other than a specific person using image data including the surroundings of the display device, and a state change step of changing an output state of the target information on the display device in response to the detection of the situation. The display device displays screen data transmitted via a network. The process of changing the output state of the target information is a process of processing the screen data in a relay device that relays the transmission of the screen data transmitted from a device that is a source of the screen data. Effect of the Invention

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

[0012] [Figure 1] 1 is a diagram illustrating an example of an overview of a display control device according to a first embodiment. [Diagram 2] FIG. 2 is a block diagram illustrating a functional configuration of a display control device. [Diagram 3] FIG. 2 is a block diagram illustrating a hardware configuration of a computer that realizes a display control device. [Figure 4] 4 is a flowchart illustrating a flow of processing executed by the display control device of the first embodiment. [Diagram 5] FIG. 11 is a diagram illustrating a case in which target information is provided via a network. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[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 duplicated descriptions will be omitted as necessary for clarity of explanation.

[0014] Fig. 1 is a diagram illustrating an example of an overview of a display control device (a display control device 2000 in Fig. 2 described later) according to the first embodiment. Note that the following description given with reference to Fig. 1 is intended to facilitate understanding of the display control device 2000 according to the first embodiment, and the operation of the display control device 2000 according to the first embodiment is not limited to that described below.

[0015] The display control device 2000 controls the display of information by the display device 10. Hereinafter, information whose display is controlled by the display control device 2000 is referred to as target information. The target information may be all of the information displayed on the display device 10, or may be a part of the information. The target information is information that should not be viewed by anyone other than those permitted to view it. For example, the target information is information that is permitted to be viewed only by employees, or information that is permitted to be viewed only by a specific group.

[0016] The display control device 2000 detects 1) that the target information displayed on the display device 10 is in a first situation where there is a risk that it may be viewed by a person other than the specific person 30, or 2) that the target information displayed on the display device 10 is in a second situation where there is a risk that it may be captured by a camera. 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 a "predetermined situation." It is noted that a plurality of specific persons 30 may be defined.

[0017] The first situation and the second situation are detected by using sensor data obtained from the sensor 20. The sensor 20 is provided so as to obtain data related to the situation around the display device 10 as sensor data. For example, the sensor 20 is a camera or a microphone. 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 making it difficult to view the target information. 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 darkening the brightness of the display of the display device 10 or processing the display.

[0019] For example, in case 1 of Fig. 1, a first situation is detected when a person other than the specific person 30 appears in a position where the display device 10 can be viewed. As a result, information is no longer displayed on the display device 10. In case 2 of Fig. 1, a second situation is detected when the specific person 30 attempts to capture an image of the information displayed on the display device 10 with the camera of his / her smartphone. As a result, a control process is performed to superimpose a dot pattern on the information displayed on the display device 10.

[0020] In Fig. 1, in order to show variations in display control, the display control is different when a first situation is detected and when a 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] In this way, the display control device 2000 of this embodiment detects 1) a situation in which 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 in which the target information displayed on the display device 10 may be captured by a camera, and in response to the detection, it is possible to make the target information displayed on the display device 10 unviewable or to reduce the visibility of the target information. This makes it possible to prevent leakage of the target information displayed on the display device 10.

[0022] The display control device 2000 of this embodiment will be described in more detail below.

[0023] <Example of functional configuration> 2 is a block diagram illustrating a functional configuration of the display control device 2000. The display control device 2000 has a detection unit 2020 and a state change unit 2040. The detection unit 2020 detects whether the target information displayed by the display device 10 is in a predetermined state (first state or second state) by using sensor data obtained from the sensor 20. 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 above detection. The output state after the change is a state in which the target information is not displayed or a state in which 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 that realizes each functional component (e.g., a hardwired electronic circuit, etc.), 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.). Below, a further description will be given of the case where each functional component of the display control device 2000 is realized by a combination of hardware and software.

[0025] 3 is a block diagram illustrating a hardware configuration of a computer 500 that realizes the display control device 2000. The computer 500 is any computer. For example, the computer 500 is a stationary computer such as a PC (Personal Computer) or a server machine. Alternatively, the computer 500 is a portable computer such as a smartphone or a tablet terminal. Alternatively, 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 in the computer 500, each function of the display control device 2000 is realized by the computer 500. The application is constituted by a program for realizing the functional components of the display control device 2000.

[0027] The computer 500 has 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 other components to each other is not limited to a bus connection.

[0028] The processor 504 is a processor such as a central processing unit (CPU), a graphics processing unit (GPU), or a field-programmable gate array (FPGA). The memory 506 is a main storage device realized using a random access memory (RAM) or the like. The storage device 508 is an auxiliary storage device realized using a hard disk, a solid state drive (SSD), a memory card, or a read only memory (ROM) or the like.

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

[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 for realizing the above-mentioned application) for realizing each functional component of the display control device 2000. The processor 504 reads the program into the memory 506 and executes it to realize each functional component of the display control device 2000.

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

[0033] <Processing flow> 4 is a flowchart illustrating a process flow executed by the display control device 2000 of the first embodiment. The detection unit 2020 acquires sensor data from the sensor 20 (S102). The detection unit 2020 uses the sensor data to determine whether a predetermined situation has occurred (S104). If it is determined that the predetermined situation has occurred (S104: YES), the state change unit 2040 executes a control process so as to change the output state of the target information on the display device 10 (S106).

[0034] <Detection of a given situation> The detection unit 2020 uses the sensor data obtained from the sensor 20 to determine whether or not a predetermined situation has occurred. As described above, the predetermined situation is a first situation (a situation in which the target information displayed on the display device 10 may be viewed by a person other than the specific person 30) or a second situation (a situation in which the target information displayed on the display device 10 may be captured by a camera). Below, examples of detection methods for each of the first situation and the second situation will be described.

[0035] <<How to detect 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 using sensor data obtained from the sensor 20. This will be specifically described below.

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

[0037] The camera is provided so that its imaging range includes a place where the display device 10 can be viewed. The camera may be built into the display device 10, or may be installed around the display device 10.

[0038] The image data here includes video frames constituting the video data. That is, the sensor data may be still image data generated by a still camera, or may be video data generated by a video camera. 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 (e.g., 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 equal to or less than the threshold, the detection unit 2020 determines that the first situation has not occurred.

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

[0041] <<<Cases where a microphone is used>>> A case will be described in which a microphone is used as the sensor 20. In this case, the sensor data is audio data. The microphone is provided so as to detect audio around the display device 10. In particular, it is preferable that the microphone is provided so as to detect audio coming from the direction in which a 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 a method for acquiring audio data from the microphone.

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

[0043] In addition, for example, when the voice data includes a voice of a person 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 a voice feature (hereinafter, voice feature) for the voice of each person included in the voice data. The detection unit 2020 compares the voice feature of each person detected from the voice data with the voice feature of the specific person 30 stored in advance in a storage device accessible from the detection unit 2020. When the voice feature of each person included in the voice data includes a voice feature that does not match the voice feature of the specific person 30 (for example, the similarity is less than a threshold), the detection unit 2020 determines that the first situation has occurred. On the other hand, when all of the voice feature of each person included in the voice data match the voice feature of the specific person 30 (for example, the similarity is equal to or greater than a threshold), the detection unit 2020 determines that the first situation has not occurred.

[0044] <<How to detect the second situation>> The second situation can be detected by detecting the presence of a camera other than the camera provided as the sensor 20 using sensor data obtained from the sensor 20. For example, a camera is used as the sensor 20. In this case, the detection unit 2020 determines that the second situation has occurred if a specific type of object capable of capturing an image of the display screen of the display device 10 is included in image data obtained as sensor data. The specific type of object is a camera or an object that may have a camera (for example, a mobile terminal such as a smartphone or a tablet terminal). In this case, image feature amounts of the specific type of object are stored in a storage device accessible from the detection unit 2020.

[0045] The detection unit 2020 judges whether or not image features of a specific type of object are included in image data obtained from a camera provided as the sensor 20. If it is judged that the image features of a specific type of object are included, the detection unit 2020 judges that the second situation has occurred. On the other hand, if it is judged that the image features of a specific type of object are not included, the detection unit 2020 judges that the second situation has not occurred.

[0046] <Switch between 30 specific people> The specific person 30 may be different for each piece of target information. For example, for target information called file A, the user U1 may be the specific person 30, and for target information called file B, the user U2 may be the specific person 30. In this case, a pair of identification information of the target information and identification information of the specific person 30 (for example, the image feature of the specific person 30 described above and the voice feature 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 detects a predetermined situation using the acquired identification information of the specific person 30.

[0047] <Timing for detecting a given situation> The detection unit 2020 may constantly repeat the detection of the predetermined situation (for example, perform the detection process at every predetermined time), or may perform the detection of the predetermined situation only when a predetermined condition is satisfied. For example, it is assumed that the target information is limited to a part of the information, not all of the information. In this case, the detection unit 2020 performs the process of detecting the predetermined situation only when the target information is displayed on the display device 10. In this case, the identification information of each piece of information (for example, a file) treated as the target information is stored in advance in a storage device accessible from the detection unit 2020. The detection unit 2020 acquires the identification information of each piece of information displayed on the display device 10 at the timing of detecting the predetermined situation, and determines whether or not 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 the predetermined situation. On the other hand, if the identification information of the target information is not included, the detection unit 2020 does not detect the predetermined situation.

[0048] Furthermore, the detection unit 2020 may constantly repeat detection of the predetermined situation, and may add a condition that "target information is displayed on the display device 10" to the conditions for detecting the predetermined situation. For example, the detection unit 2020 determines that the first situation has occurred when the condition that "target information is displayed on the display device 10, and a person other than the specific person 30 is included in the image data obtained from the camera" is satisfied.

[0049] <Change 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 all information is not output from the display device 10. In this way, all information displayed on the display device 10 cannot be viewed, so that people other than the specific person 30 cannot view the target information. In addition, it is also impossible to capture the target information with a camera. Such control processing is, for example, processing to turn off the power of the display device 10 or block transmission of screen data to the display device 10.

[0050] Additionally, for example, the state change unit 2040 performs a control process so as to reduce the visibility of the information output from the display device 10. In this way, even if a person other than the specific person 30 views the target information, it is possible to make it difficult for the person to understand the content. Similarly, even if the target information is captured by a camera, it is possible to make it difficult for the person to understand the content of the captured information.

[0051] The control process for reducing the visibility of information is, for example, a process for reducing the brightness of the display device 10, or a process for processing the screen data displayed on the display device 10. The processing applied to the screen data is, for example, a process for changing the color tone of the screen data (e.g., changing to a darker color overall), a process for superimposing other image data (e.g., a dot pattern) on the screen data, or a process for modifying the screen data according to a predetermined algorithm (e.g., applying a mosaic).

[0052] 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 of only the target information. Such processing is, for example, processing to minimize the window of the target information, processing to make the window transparent (to set the opacity to zero), etc. Also, the processing applied to the screen data described above may be applied only to the window of the target information.

[0053] There are various targets to which the state change unit 2040 applies control for the above-mentioned control process. For example, the state change unit 2040 controls the hardware of the display device 10. For example, the state change unit 2040 can turn off the power of the display device 10 to prevent information from being displayed on the display device 10, or can reduce the visibility of information displayed on the display device 10 by lowering the brightness of the display device 10. In addition, for example, the state change unit 2040 may control a machine (e.g., 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, the process of blocking the output of screen data to the display device 10 or processing the screen data can be performed by a program (e.g., a device driver) in an operating system running on the machine that outputs the screen data.

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

[0055] In this case, screen data generated by company machine 110 is sent to home machine 100 via company VPN device 120 and home VPN device 130. The screen data is then output from home machine 100 to display device 10. The above-mentioned control processing can be realized by blocking the transmission of screen data or processing the screen data in any one of company machine 110, company VPN device 120, or home VPN device 130.

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

[0057] Alternatively, the home machine 100 may be provided with the function of the detection unit 2020, and the company machine 110, the company VPN device 120, or the home VPN device 130 may be provided with the function of the state change unit 2040. In this case, the home machine 100 detects a specific situation and notifies a device provided with the function of the state change unit 2040 that the specific situation has been detected. Then, the device that receives the notification performs processing to control the display.

[0058] Although the present invention has been described above with reference to the embodiment, the present invention is not limited to the above embodiment. Various modifications 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 and provided to the computer using various types of non-transitory computer readable media. The non-transitory computer readable medium includes various types of tangible storage media. Examples of the non-transitory computer readable medium include magnetic recording media (e.g., flexible disks, magnetic tapes, hard disk drives), magneto-optical recording media (e.g., magneto-optical disks), CD-ROMs, CD-Rs, CD-R / Ws, and semiconductor memories (e.g., mask ROMs, PROMs (Programmable ROMs), EPROMs (Erasable PROMs), flash ROMs, and RAMs). The program may also be provided to the computer by various types of transitory computer readable media. Examples of the transitory computer readable medium include electrical signals, optical signals, and electromagnetic waves. The transitory computer readable medium can supply the program to the computer via a wired communication path such as an electric wire or optical fiber, or via a wireless communication path.

[0060] A part or all of the above-described embodiments can be described as, but is not limited to, the following supplementary notes. (Appendix 1) a detection unit that detects a first situation in which target information displayed on the display device may 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 on the display device may be captured by a camera, using image data including the surroundings of the display device; a state change unit that changes an output state of the target information on the display device in response to detection of the first situation or the second situation, A display control device, wherein the change in the output state is a process of stopping output of the target information or a process of lowering visibility of the target information compared to before the change. (Appendix 2) The display control device described in Appendix 1, wherein the detection unit determines that the first situation has occurred when a number of human voices equal to or greater than a predetermined threshold are detected from the voice data, or when a voice with voice features that do not match the voice features of the specific person's voice is detected from the voice data. (Appendix 3) The detection unit is acquiring, from a storage device storing a plurality of correspondences 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; A display control device as described in Appendix 2, which detects the first situation when the voice data contains voice features that do not match the acquired voice features of the specific person. (Appendix 4) The display control device described in Appendix 1, wherein the detection unit determines that the second situation has occurred when image features of a specific type of object capable of capturing the target information displayed on the display device are detected from the image data. (Appendix 5) The display control device according to any one of claims 1 to 4, wherein the detection unit detects the first situation or the second situation only when the target information is displayed on the display device. (Appendix 6) A display control device according to any one of appendixes 1 to 5, wherein 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 screen data output to the display device. (Appendix 7) the display device displays screen data transmitted via a network; The display control device according to any one of appendices 1 to 6, wherein the state change unit is a process of blocking transmission of the screen data or processing the screen data in a device that is the source of the screen data or in a device that relays the transmission of the screen data by that device. (Appendix 8) The display control device according to any one of claims 1 to 7, wherein the display control device is provided inside the display device. (Appendix 9) A display control method executed by a computer, comprising: a detection step of detecting a first situation in which target information displayed on the display device may be viewed by a person other than a specific person, using audio data including sounds around the display device, or detecting a second situation in which the target information displayed on the display device may be captured by a camera, using image data including the surroundings of the display device; a state changing step of changing an output state of the target information on the display device in response to detection of the first state or the second state, A display control method, wherein the change in the output state is a process of stopping output of the target information or a process of lowering visibility of the target information compared to before the change. (Appendix 10) The display control method of claim 9, wherein, in the detection step, if a number of human voices equal to or greater than a predetermined threshold are detected from the audio data, or if a voice with audio features that do not match the audio features of the specific person's voice is detected from the audio data, it is determined that the first situation has occurred. (Appendix 11) In the detection step, acquiring, from a storage device storing a plurality of correspondences 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; The display control method according to claim 10, wherein the first situation is detected when the voice data contains voice features that do not match the acquired voice features of the specific person. (Appendix 12) The display control method of claim 9, wherein, in the detection step, if an image feature of a specific type of object capable of capturing the target information displayed on the display device is detected from the image data, it is determined that the second situation has occurred. (Appendix 13) A display control method according to any one of appendices 9 to 12, wherein in the detection step, detection of the first situation or the second situation is performed only when the target information is displayed on the display device. (Appendix 14) A display control method according to any one of appendixes 9 to 13, wherein 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 screen data output to the display device. (Appendix 15) the display device displays screen data transmitted via a network; A display control method according to any one of appendices 9 to 14, wherein in the state change step, a device that is a source of the screen data or a device that relays the transmission of the screen data by that device blocks the transmission of the screen data or processes the screen data. (Appendix 16) The display control method according to any one of claims 9 to 15, wherein the computer is provided inside the display device. (Appendix 17) A computer-readable medium storing a program, The program includes: a detection step of detecting a first situation in which target information displayed on the display device may be viewed by a person other than a specific person, using audio data including sounds around the display device, or detecting a second situation in which the target information displayed on the display device may be captured by a camera, using image data including the surroundings of the display device; a state changing step of changing an output state of the target information on the display device in response to detection of the first state or the second state; A computer-readable medium, wherein the change in the output state is a process of stopping output of the target information or a process of lowering the visibility of the target information compared to before the change. (Appendix 18) 18. The computer-readable medium of claim 17, wherein in the detection step, it is determined that the first situation has occurred when a number of human voices equal to or greater than a predetermined threshold are detected from the voice data, or when a voice with voice features that do not match the voice features of the specific person's voice is detected from the voice data. (Appendix 19) In the detection step, acquiring, from a storage device storing a plurality of correspondences 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; 19. The computer-readable medium of claim 18, wherein the first situation is detected when the voice data contains voice features that do not match the acquired voice features of the specific person. (Appendix 20) 18. The computer-readable medium of claim 17, wherein in the detection step, when an image feature of a specific type of object capable of capturing the target information displayed on the display device is detected from the image data, it is determined that the second situation has occurred. (Appendix 21) 21. The computer-readable medium of any one of appendixes 17 to 20, wherein in the detection step, detection of the first situation or the second situation is performed only when the target information is displayed on the display device. (Appendix 22) A computer-readable medium according to any one of appendices 17 to 21, wherein 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 screen data output to the display device. (Appendix 23) the display device displays screen data transmitted via a network; 23. The computer-readable medium of any one of appendices 17 to 22, wherein the state change step is a process of blocking transmission of the screen data or processing the screen data in a device that is a source of the screen data or in a device that relays the transmission of the screen data by that device. (Appendix 24) 24. The computer-readable medium of any one of claims 17 to 23, wherein the computer is provided within the display device. [Explanation of symbols]

[0061] 10 Display device 20 Sensors 30 Specific person 100 Home machine 110 Company machine 120 equipment 130 Equipment 500 Computers 502 Bus 504 Processor 506 Memory 508 Storage Devices 510 Input / Output Interface 512 Network Interface 2000 Display Control Device 2020 Detection section 2040 State change section

Claims

1. a detection unit that detects a situation in which target information displayed on the display device may be viewed by a person other than a specific person, using image data including a surrounding area of ​​the display device; a state change unit that changes an output state of the target information on the display device in response to the detection of the situation, the display device displays screen data transmitted via a network; A display control device, wherein the process of changing the output state of the target information is a process of blocking the transmission of the screen data in a relay device that relays the transmission of the screen data transmitted from the device that sent the screen data.

2. A display control method executed by a computer, comprising: A detection step of detecting a situation in which target information displayed on the display device may be viewed by a person other than a specific person, using image data including a surrounding area of ​​the display device; and a state changing step of changing an output state of the target information on the display device in response to the detection of the situation, the display device displays screen data transmitted via a network; A display control method, wherein the process of changing the output state of the target information is a process of blocking the transmission of the screen data in a relay device that relays the transmission of the screen data transmitted from the device that sent the screen data.

3. A detection step of detecting a situation in which target information displayed on the display device may be viewed by a person other than a specific person, using image data including a surrounding area of ​​the display device; a state changing step of changing an output state of the target information on the display device in response to the detection of the situation; the display device displays screen data transmitted via a network; The program, wherein the process of changing the output state of the target information is a process of blocking transmission of the screen data in a relay device that relays the transmission of the screen data transmitted from a device that is a source of the screen data.

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