Screen sharing device, screen sharing method, and program

Abstract

A screen sharing device according to one embodiment comprises: a calculation unit that calculates a first similarity between first screen information shared between a first terminal and a second terminal at a first time and second screen information generated by the first terminal after the first time; a selection unit that selects, from the first screen information and the second screen information, the screen information to be shared between the first terminal and the second terminal at a second time after the first time, on the basis of the first similarity and the elapsed time since the most recent user input to the first terminal; and a transfer unit that transfers the selected screen information to the second terminal.

Description

Screen sharing device, screen sharing method, and program

[0001] The embodiments relate to a screen sharing device, a screen sharing method, and a program.

[0002] Network-based conferencing tools have become popular as a means of achieving smooth communication between business associates in remote work styles such as telecommuting. These conferencing tools have a screen-sharing function that allows users to share their device screens in real time with other meeting participants, in addition to their voices. This allows for online meetings with colleagues and business partners, as well as product and service presentations at events.

[0003] On the other hand, the terminal is equipped with an application that has a notification function that notifies the user of information in real time. The notification function of such an application realizes real-time notification of information to the user by displaying notification information on the screen so as to overwrite part of the information presented by other applications used by the user.

[0004] “I don’t want people to see Google Chrome’s web notifications while I’m sharing my screen. Here’s the solution! [Today’s Work Hack]” URL: https: / / news.yahoo.co.jp / articles / 51fadd2deccb902d1db42e729483724259f69f6b

[0005] If the information displayed by the notification function is information that should not be made public to the participants of the conference, it is not desirable for the notification information to be unintentionally displayed on the screen during the conference, as this could lead to information leakage.

[0006] Some applications allow users to temporarily disable their notification functions. However, to eliminate the risk of information leakage while still using the notification functions, users must disable the application's notification functions before starting screen sharing and then re-enable them afterward. Therefore, users who find this series of operations cumbersome may neglect to perform these operations even if they understand the need for information management. Furthermore, users may not realize that the notification functions have been enabled due to application settings being reset after an update, for example.

[0007] In addition, some applications detect the start of screen sharing and automatically turn off the notification function. However, unless all applications with notification functions have this function, the risk of information leakage remains.

[0008] The present invention has been made in light of the above-mentioned circumstances, and its object is to provide a means for reducing the risk of information leakage that accompanies screen sharing.

[0009] A screen sharing device according to one aspect includes a calculation unit, a determination unit, and a transfer unit. The calculation unit calculates a first similarity between first screen information shared between a first terminal and a second terminal at a first time and second screen information generated by the first terminal after the first time. The determination unit determines, from the first screen information and the second screen information, screen information to be shared between the first terminal and the second terminal at a second time after the first time, based on the first similarity and an amount of time elapsed since the most recent user input to the first terminal. The transfer unit transfers the determined screen information to the second terminal.

[0010] According to the embodiment, it is possible to provide a means for reducing the risk of information leakage that accompanies screen sharing.

[0011] FIG. 1 is a diagram illustrating an example of a screen sharing system according to an embodiment. FIG. 2 is a block diagram illustrating an example of the hardware configuration of a terminal according to an embodiment. FIG. 3 is a block diagram illustrating an example of the hardware configuration of a screen sharing device according to an embodiment. FIG. 4 is a block diagram illustrating an example of the functional configuration of a terminal and a screen sharing device according to an embodiment. FIG. 5 is a flowchart illustrating an example of screen sharing processing in the screen sharing device according to an embodiment. FIG. 6 is a diagram illustrating an example of a case where screen information shared in the screen sharing processing in the screen sharing device according to an embodiment is updated. FIG. 7 is a diagram illustrating an example of a case where screen information shared in the screen sharing processing in the screen sharing device according to an embodiment is not updated. FIG. 8 is a flowchart illustrating an example of screen sharing processing in a terminal according to a first modified example. FIG. 9 is a block diagram illustrating an example of the functional configuration of a screen sharing system according to a second modified example.

[0012] Hereinafter, embodiments will be described with reference to the drawings. In the following description, components having the same functions and configurations will be given the same reference numerals.

[0013] 1. Embodiment 1.1 Screen Sharing System FIG. 1 is a diagram showing an example of a screen sharing system according to an embodiment.

[0014] The screen sharing system 1 is, for example, an online conference system that enables multiple users to share audio and screens in real time. The screen sharing system 1 includes terminals 10A and 10B and a screen sharing device 20. The terminals 10A and 10B and the screen sharing device 20 are configured to communicate with each other via a network NW.

[0015] Each of the terminals 10A and 10B is a personal computer, a smartphone, or the like. The terminals 10A and 10B are used by users UA and UB, respectively. The users UA and UB use the terminals 10A and 10B to hold an online conference via a network NW. The following describes a case where screen information displayed on the display of the terminal 10A during the online conference is shared by the terminal 10B.

[0016] The screen sharing device 20 is, for example, a server that manages an online conference held in the screen sharing system 1. For example, the screen sharing device 20 acquires (unmodified) screen information displayed on the display of the terminal 10A from the terminal 10A, along with input information (user input) to the terminal 10A by the user UA. The screen sharing device 20 modifies the screen information acquired from the terminal 10A based on the screen information and the user input. The modified screen information is screen information from which information unrelated to the content of the conference has been removed from the unmodified screen information. The screen sharing device 20 presents the modified screen information to the user UB via the terminal 10B. As a result, screen information related to the content of the conference is shared in real time between the users UA and UB.

[0017] 1.2 Hardware Configuration Next, the hardware configuration of the terminal and the screen sharing device according to the embodiment will be described.

[0018] 2 is a block diagram showing an example of the hardware configuration of a terminal according to an embodiment. As shown in FIG. 2, each of the terminals 10A and 10B includes a control circuit 11, a communication module 12, and a user interface 13. The terminals 10A and 10B have the same configuration. Hereinafter, when there is no particular need to distinguish between the terminals 10A and 10B, they will be referred to as terminals 10. Similarly, when there is no particular need to distinguish between the users UA and UB, they will be referred to as users U.

[0019] The control circuit 11 is a circuit that controls the overall components of the terminal 10. The control circuit 11 includes a CPU (Central Processing Unit), RAM (Random Access Memory), and ROM (Read Only Memory). The ROM of the control circuit 11 stores programs and the like used in various processes in the terminal 10. The CPU of the control circuit 11 controls the entire terminal 10 in accordance with the programs stored in the ROM of the control circuit 11. The RAM of the control circuit 11 is used as a working area for the CPU of the control circuit 11.

[0020] The communication module 12 is a circuit used for communicating data with other terminals 10 and for sending and receiving data between the terminal 10 and the screen sharing device 20 .

[0021] The user interface 13 is an interface that manages communication between the user U and the control circuit 11. The user interface 13 includes input devices and output devices. The input devices include, for example, an audio microphone, a touch panel, a keyboard, a mouse, and operation buttons. The output devices include, for example, a speaker and a display. The user interface 13 converts user input into an electrical signal and then transmits it to the control circuit 11. The user interface 13 outputs screen information displayed on the display to the user U.

[0022] 3 is a block diagram showing an example of the hardware configuration of a screen sharing device according to an embodiment. As shown in FIG. 3, the screen sharing device 20 includes a control circuit 21, a communication module 22, a storage 23, a drive 24, and a storage medium 25.

[0023] The control circuit 21 is a circuit that controls the overall components of the screen sharing device 20. The control circuit 21 includes a CPU, RAM, ROM, etc. The ROM of the control circuit 21 stores programs and the like used in various processes in the screen sharing device 20. The CPU of the control circuit 21 controls the overall screen sharing device 20 in accordance with the programs stored in the ROM of the control circuit 21. The RAM of the control circuit 21 is used as a working area for the CPU of the control circuit 21.

[0024] The communication module 22 is a circuit used for transmitting and receiving data between the screen sharing device 20 and the terminal 10 .

[0025] The storage 23 includes, for example, a hard disk drive (HDD) or a solid state drive (SSD). The storage 23 stores information used in various processes in the screen sharing device 20.

[0026] The drive 24 is a device for reading software stored in the storage medium 25. The drive 24 includes, for example, a CD (Compact Disk) drive or a DVD (Digital Versatile Disk) drive.

[0027] The storage medium 25 is a medium that stores software electrically, magnetically, optically, mechanically, or chemically. The storage medium 25 may store programs for executing various processes in the screen sharing device 20.

[0028] 1.3 Functional Configuration Fig. 4 is a block diagram illustrating an example of the functional configuration of the terminal and the screen sharing device according to the embodiment. The example of Fig. 4 illustrates an example of the functional configuration when the terminal 10A functions as a sharing source of screen information and the terminal 10B functions as a sharing destination of screen information.

[0029] 4 , the terminal 10A functions as a computer including a user input acquisition unit 31, a notification information acquisition unit 32, and a generation unit 33. The screen sharing device 20 stores a transfer screen history 41. The screen sharing device 20 functions as a computer including a similarity calculation unit 42, a determination unit 43, and a transfer unit 44. The terminal 10B functions as a computer including a display unit 51.

[0030] First, the functional configuration of the terminal 10A will be described.

[0031] The user input acquisition unit 31 acquires user input entered by the user UA. Specific examples of user input include pressing a button on a keyboard or touch panel, clicking a mouse, etc. The user input acquisition unit 31 also acquires the acquisition time of the acquired user input. The user input acquisition unit 31 then inputs the acquired user input and the acquisition time to the generation unit 33 and the determination unit 43.

[0032] The notification information acquisition unit 32 acquires notification information from an external terminal (not shown) via the network NW. The notification information is, for example, information that is displayed as a pop-up on a display, such as a message received in real time. The notification information acquisition unit 32 inputs the acquired notification information to the generation unit 33.

[0033] The generation unit 33 generates screen information to be displayed on the display based on the acquired user input and notification information. The screen information is generated, for example, at each screen update time that is set at a predetermined interval. The generation unit 33 inputs the generated screen information to the similarity calculation unit 42.

[0034] The screen information generated by the generation unit 33 includes information related to the participants of the online conference, such as text displayed in response to user input and slides used in a presentation. The screen information generated by the generation unit 33 also includes notification information that is displayed as a pop-up so as to overwrite part of the information related to the online conference. Therefore, the screen information generated by the generation unit 33 may include information that is not related to the participants of the online conference. Such information that is not related to the participants of the online conference may pose a risk of information leakage.

[0035] Next, the functional configuration of the screen sharing device 20 will be described.

[0036] The transfer screen history 41 stores a history of screen information (transfer screen information) that has been transferred to the terminal 10B in the past as screen information to be shared.

[0037] When screen information (generated screen information) is input from the generation unit 33, the similarity calculation unit 42 calculates the similarity between the generated screen information and the transfer screen information. The more parts that match between the generated screen information and the transfer screen information, the higher the similarity calculation unit 42 calculates. Conversely, the more parts that differ between the generated screen information and the transfer screen information, the lower the similarity calculation unit 42 calculates. The similarity calculation unit 42 inputs the calculated similarity to the determination unit 43.

[0038] The determination unit 43 manages the elapsed time from the most recent input time included in the user input input from the user input acquisition unit 31. The determination unit 43 also determines whether the calculated similarity is less than a threshold. If the similarity is equal to or greater than the threshold, the determination unit 43 determines that there is no significant difference between the generated screen information and the transfer screen information, and inputs the transfer screen information used to calculate the similarity to the transfer unit 44. If the similarity is less than the threshold, the determination unit 43 further determines whether the elapsed time from the most recent input time of the user input is less than a threshold. If the elapsed time from the most recent input time of the user input is less than the threshold, the determination unit 43 determines that the difference between the generated screen information and the transfer screen information is due to the user input, and inputs the generated screen information to the transfer unit 44. If the elapsed time from the most recent input time of the user input is equal to or greater than the threshold, the determination unit 43 determines that the difference between the generated screen information and the transfer screen information is due to the display of notification information, and inputs the transfer screen information used to calculate the similarity to the transfer unit 44. The threshold value for the elapsed time from the user input may be set to, for example, a value greater than the screen update interval. Such a threshold value for the elapsed time from the user input may be set in advance as a constant when the screen sharing device 20 is started up, for example.

[0039] The transfer unit 44 transfers the screen information input from the determination unit 43 to the display unit 51. In other words, if there is no significant difference between the transferred screen information and the generated screen information, or if a significant difference occurs due to the display of notification information, the transfer unit 44 continues to transfer the transferred screen information used in the similarity calculation to the display unit 51. On the other hand, if a significant difference occurs between the transferred screen information and the generated screen information due to a user input, the transfer unit 44 transfers the generated screen information to the display unit 51.

[0040] Next, the functional configuration of the terminal 10B will be described.

[0041] The display unit 51 displays the transferred screen information transferred from the transfer unit 44 on the display.

[0042] With the above configuration, users UA and UB can share screen information from which notification information that user UB should not share has been removed.

[0043] 1.2 Operation Next, the operation of the screen sharing device according to the embodiment will be described.

[0044] 5 is a flowchart showing an example of the screen sharing process in the screen sharing device according to the embodiment. Note that, prior to the screen sharing process, the user input acquisition unit 31 and the notification information acquisition unit 32 start acquiring user input and notification information, respectively.

[0045] When the screen update time arrives (starts), the screen sharing device 20 acquires screen information that takes into account the user input and notification information from the generation unit 33 of the terminal 10A (S11). As a result, the screen sharing device 20 acquires screen information (generated screen information) that may include text and slides according to the user input, and messages to be overwritten on the screen according to the notification information.

[0046] The similarity calculation unit 42 calculates the similarity between the screen information generated in the processing of S11 and the screen information (transfer screen information) previously transferred to the terminal 10B by referring to the transfer screen history 41 (S12).

[0047] The determination unit 43 determines whether the similarity calculated in the process of S12 is less than a threshold value (S13).

[0048] If the similarity is less than the threshold value (S13; yes), the determination unit 43 determines whether the time elapsed since the most recent acquisition time of the user input is less than the threshold value (S14).

[0049] If the elapsed time since the most recent acquisition time of the user input is less than the threshold value (S14; yes), the determination unit 43 determines that the difference between the generated screen information and the transferred screen information is due to the user input. Then, based on the determination result, the transfer unit 44 transfers the screen information generated in the process of S11 to the sharing destination terminal 10B. As a result, the terminal 10A and the terminal 10B share the screen information generated in the process of S11 (S15).

[0050] If the similarity is equal to or greater than the threshold (S13; no), the determination unit 43 determines that there is no significant difference between the screen information generated in the process of S11 and the screen information previously transferred. Then, based on the determination result, the transfer unit 44 transfers the previously transferred screen information to the sharing destination terminal 10B. As a result, the terminals 10A and 10B continue sharing the previously transferred screen information (S16).

[0051] If the elapsed time since the most recent acquisition time of the user input is equal to or greater than the threshold value (S14; no), the determination unit 43 determines that the difference between the generated screen information and the transferred screen information is due to the display of the notification information. Then, based on the determination result, the transfer unit 44 transfers the previously transferred screen information to the sharing destination terminal 10B. As a result, the terminals 10A and 10B continue to share the previously transferred screen information (S16).

[0052] After the process of S15 or S16, the screen sharing device 20 determines whether the sharing of the screen information has ended (S17).

[0053] If the sharing of the screen information has not ended (S17; no), the screen sharing device 20 waits until the next screen update time (S18).

[0054] When the next screen update time arrives, the screen sharing device 20 receives the screen information newly generated by the generation unit 33 of the terminal 10A, taking into account the user input and notification information (S11). Then, the subsequent processes of S12 to S18 are executed. In this way, the processes of S11 to S18 are repeatedly executed until the sharing of the screen information is completed.

[0055] If the sharing of the screen information has ended (S17; yes), the screen sharing process ends (end).

[0056] 1.2.2 Specific Example Next, a specific example of the screen sharing process in the screen sharing device according to the embodiment will be described.

[0057] Fig. 6 is a diagram showing an example of a case where shared screen information is updated in the screen sharing process in the screen sharing device according to the embodiment. Fig. 7 is a diagram showing an example of a case where non-shared screen information is updated in the screen sharing process in the screen sharing device according to the embodiment. Fig. 6 corresponds to the case of "S14; yes" in the flowchart shown in Fig. 5. Fig. 7 corresponds to the case of "S14; no" in the flowchart shown in Fig. 5.

[0058] First, the case of "S14: yes" will be described with reference to FIG.

[0059] 6 , at time T1, screen information in which a window corresponding to a line graph is selected is shared between terminals 10A and 10B as transferred screen information. Then, between time T1 and time T2, user input acquisition unit 31 acquires a user input to change the selected window. Accordingly, at time T2, which is the next screen update time, generation unit 33 generates screen information in which a window corresponding to a bar graph is selected.

[0060] The similarity calculation unit 42 compares the transfer screen information shared at time T1 with the generated screen information related to time T2 and calculates a similarity lower than a threshold. The determination unit 43 determines, based on the calculated similarity, that there is a significant difference between the transfer screen information and the generated screen information. Therefore, the determination unit 43 determines whether the elapsed time since the most recent user input is less than a threshold. In the example of FIG. 6 , the elapsed time since the user input is less than the threshold. As a result, the determination unit 43 determines that the significant difference between the transfer screen information and the generated screen information is based on the user input. Therefore, the determination unit 43 determines that the difference in the screen information should be shared between users UA and UB and inputs the generated screen information to the transfer unit 44. In this way, generated screen information different from the transfer screen information shared at time T1 is shared at time T2.

[0061] Next, the case of "S14: no" will be described with reference to FIG.

[0062] 7, at time T3, screen information in which a window corresponding to a line graph is selected is shared between terminals 10A and 10B as transfer screen information. Then, between time T3 and time T4, notification information acquisition unit 32 acquires a message including information that should not be shared with user UB. Accordingly, at time T4, which is the next screen update time, generation unit 33 generates screen information in which the notification information has been overwritten.

[0063] The similarity calculation unit 42 compares the transfer screen information shared at time T3 with the generated screen information related to time T4 and calculates a similarity lower than a threshold. Based on the calculated similarity, the determination unit 43 determines that there is a significant difference between the transfer screen information and the generated screen information. Therefore, the determination unit 43 determines whether the elapsed time since the most recent user input is less than a threshold. In the example of FIG. 6 , the elapsed time since the user input is equal to or greater than the threshold. As a result, the determination unit 43 determines that the significant difference between the transfer screen information and the generated screen information is based on the notification information. Therefore, the determination unit 43 determines that the change in the screen information should not be shared between users UA and UB and inputs the transfer screen information shared at time T3 to the transfer unit 44. In this way, the same screen information as the transfer screen information shared at time T3 continues to be shared at time T4.

[0064] 1.3 Effects of the Embodiment According to the embodiment, the similarity calculation unit 42 calculates the similarity between first screen information, which is transferred screen information shared between terminals 10A and 10B at a first time, and second screen information, which is generated screen information generated by terminal 10A after the first time. The determination unit 43 determines, from the first screen information and the second screen information, the screen information to be shared between terminals 10A and 10B at a second time after the first time, based on the calculated similarity and the elapsed time since the most recent user input to terminal 10A, including the most recent key press and mouse click. The transfer unit 44 transfers the screen information selected as a result of the determination to terminal 10B.

[0065] Specifically, if there is a significant difference between the first screen information and the second screen information and the elapsed time is equal to or greater than a threshold, the determination unit 43 determines that the difference is due to notification information. As a result, if there is a significant difference between the first screen information and the second screen information and the elapsed time is equal to or greater than a threshold, the first screen information continues to be shared between the terminals 10A and 10B. In this way, if the second screen information contains notification information that may include information that should not be shared between participants of the online conference, the second screen information can be prevented from being shared. On the other hand, if there is a significant difference between the first screen information and the second screen information and the elapsed time is less than a threshold, the determination unit 43 determines that the difference is due to user input. As a result, if there is a significant difference between the first screen information and the second screen information and the elapsed time is less than a threshold, the second screen information is shared between the terminals 10A and 10B. In this way, if the second screen information does not contain notification information that may include information that should not be shared between participants of the online conference, the second screen information can be shared. This reduces the risk of information leakage that comes with screen sharing, while enabling information necessary for online meetings to be shared in real time.

[0066] 2. Modifications, etc. Various modifications can be applied to the above-described embodiment.

[0067] 2.1 First Modification In the above-described embodiment, a case has been described in which it is determined that a change in screen information to be shared may occur only when the time elapsed since a user input is less than a threshold value, but this is not limited to this. For example, even if the time elapsed since a user input is equal to or greater than a threshold value (i.e., a state in which a mouse click or key press has not occurred within a predetermined period), it may be determined based on additional information whether a change in screen information to be shared has occurred.

[0068] More specifically, for example, the user input acquisition unit 31 may further acquire information indicating whether the mouse is being dragged, and the determination unit 43 may use the information indicating whether the mouse is being dragged in addition to the user input in the determination process.

[0069] 8 is a flowchart showing an example of a screen sharing process in the screen sharing device according to the first modified example, which corresponds to FIG. 5 in the embodiment.

[0070] When the screen update time arrives (starts), the screen sharing device 20 receives screen information that takes into account the user input and notification information and that is generated by the generation unit 33 of the terminal 10A (S21). As a result, the screen sharing device 20 acquires generated screen information that may include text and slides according to the user input, and messages to be overwritten on the screen according to the notification information.

[0071] The similarity calculation unit 42 calculates the similarity between the screen information generated in the process of S21 and screen information transferred in the past (S22).

[0072] The determination unit 43 determines whether the similarity calculated in the process of S22 is less than a threshold value (S23).

[0073] If the similarity is less than the threshold value (S23; yes), the determination unit 43 determines whether the time elapsed since the most recent acquisition time of the user input is less than the threshold value (S24).

[0074] If the elapsed time since the most recent acquisition time of the user input is less than the threshold value (S24; yes), the determination unit 43 determines that the difference between the generated screen information and the transferred screen information is due to the user input. Then, based on the determination result, the transfer unit 44 transfers the screen information generated in the process of S21 to the sharing destination terminal 10B. As a result, the terminal 10A and the terminal 10B share the screen information generated in the process of S21 (S25).

[0075] If the time elapsed since the most recent acquisition time of the user input is equal to or greater than the threshold value (S24; no), the determination unit 43 determines whether or not the mouse is being dragged (S26).

[0076] If the mouse is being dragged (S26; yes), the determination unit 43 determines that the difference between the generated screen information and the transferred screen information is due to a user input. Then, based on the determination result, the transfer unit 44 transfers the screen information generated in the process of S21 to the sharing destination terminal 10B. As a result, the terminals 10A and 10B share the screen information generated in the process of S21 (S25).

[0077] If the similarity is equal to or greater than the threshold (S23; no), the determination unit 43 determines that there is no significant difference between the screen information generated in the process of S11 and the screen information previously transferred. Then, based on the determination result, the transfer unit 44 transfers the previously transferred screen information to the sharing destination terminal 10B. As a result, the terminals 10A and 10B continue sharing the previously transferred screen information (S27).

[0078] If the elapsed time since the most recent user input acquisition time is equal to or greater than the threshold (S24; no) and the mouse is not being dragged (S26; no), the determination unit 43 determines that the difference between the generated screen information and the transferred screen information is due to the display of notification information. Based on the determination result, the transfer unit 44 transfers the previously transferred screen information to the sharing destination terminal 10B. As a result, terminal 10A and terminal 10B continue sharing the previously transferred screen information (S27).

[0079] After the process of S25 or S27, the screen sharing device 20 determines whether the sharing of the screen information has ended (S28).

[0080] If the sharing of the screen information has not ended (S28; no), the screen sharing device 20 waits until the next screen update time (S29).

[0081] When the next screen update time arrives, the screen sharing device 20 receives the screen information newly generated by the generation unit 33 of the terminal 10A, taking into account the user input and notification information (S21). Then, the subsequent processes of S22 to S29 are executed. In this way, the processes of S21 to S29 are repeatedly executed until the sharing of the screen information is completed.

[0082] If the sharing of the screen information has ended (S28; yes), the screen sharing process ends (end).

[0083] According to the first modification, an exception process is defined for a case where a screen change occurs within a period of time equal to or longer than a threshold value from a user input and the screen change is caused by the user input. This allows screen information that appropriately reflects the screen change caused by the user input to be shared between the terminals 10A and 10B. 2.2 Second Modification In the above-described embodiment, a case where the screen sharing process is executed in the screen sharing device 20 independent of the terminal 10A has been described, but this is not limited to this. For example, the screen sharing process may be executed by an application installed on the terminal 10A. In this case, the screen information to be shared is selected within the terminal 10A, and the selected screen information is transferred to the terminal 10B via the screen sharing device 20.

[0084] Fig. 9 is a block diagram showing an example of the functional configuration of a screen sharing system according to Modification 2. Fig. 9 corresponds to Fig. 4 in the embodiment.

[0085] 9 , the terminal 10A stores a transfer screen history 41. The terminal 10A functions as a computer including a user input acquisition unit 31, a notification information acquisition unit 32, a generation unit 33, a similarity calculation unit 42, and a determination unit 43. The screen sharing device 20 functions as a computer including a transfer unit 44. The terminal 10B functions as a computer including a display unit 51.

[0086] The functional configurations of the user input acquisition unit 31, the notification information acquisition unit 32, the generation unit 33, the transfer unit 44, and the display unit 51 are the same as those in the embodiment. The functional configurations of the similarity calculation unit 42 and the determination unit 43 are also the same as those in the embodiment, except that the entities that function as these functional configurations are applications implemented in the terminal 10A.

[0087] Even with the configuration of the second modified example, similar to the embodiment, the users UA and UB can share screen information from which notification information that should not be shared by the user UB has been removed.

[0088] 2.3 Others In the above-described embodiment, the threshold value for the elapsed time from a user input may be set in advance as a constant when the screen sharing device 20 is started up. However, this is not limited to this. For example, the threshold value for the elapsed time from a user input may be dynamically determined by actually measuring the time required from the user input until all screen changes resulting from the user input occur in several cases. In this case, the threshold value for the elapsed time from the user input may be determined based on statistics such as the average or variance of the actual measured values.

[0089] In the above-described embodiment, a case has been described in which it is determined whether to share generated screen information based on the similarity between one piece of transferred screen information and one piece of generated screen information. However, this is not limited to this. For example, the similarity between one piece of transferred screen information and each of multiple pieces of generated screen information generated at different times may be calculated. Then, the generated screen information with the highest similarity to the transferred screen information may be selected, and it may be determined whether to share the generated screen information based on the similarity between the selected generated screen information and the transferred screen information. This prevents screen information in the middle of transition from being displayed fixedly. This allows for quick switching to the screen information to be shared.

[0090] In the above-described embodiment, when a screen change continues even after a certain amount of time has elapsed since a user input, such as when playing a video, the determination unit 43 may be unable to determine that the screen change is caused by the user input. In such cases, an exception process, such as continuing to press a specified key, may be defined. By defining such an exception process, the time elapsed since the user input can be maintained below a threshold even when the video is played for a long period of time. This reduces the possibility of erroneously determining that a screen change caused by a user input is not caused by a user input.

[0091] The present invention is not limited to the above-described embodiments, and various modifications can be made in the implementation stage without departing from the spirit of the invention. Furthermore, the embodiments may be implemented in appropriate combinations, in which case the combined effects can be obtained. Furthermore, the above-described embodiments include various inventions, and various inventions can be extracted by combining selected elements from the disclosed elements. For example, if the problem can be solved and the desired effect can be obtained even if some elements are deleted from all elements shown in the embodiments, the configuration from which these elements are deleted can be extracted as an invention.

[0092] DESCRIPTION OF SYMBOLS 1...Screen sharing system 10A, 10B...Terminal 11...Control circuit 12...Communication module 13...User interface 20...Screen sharing device 21...Control circuit 22...Communication module 23...Storage 24...Drive 25...Storage medium 31...User input acquisition unit 32...Notification information acquisition unit 33...Generation unit 41...Transfer screen history 42...Similarity calculation unit 43...Determination unit 44...Transfer unit 51...Display unit

Claims

1. A screen sharing device comprising: a calculation unit that calculates a first similarity between first screen information shared between a first terminal and a second terminal at a first time and second screen information generated by the first terminal after the first time; a determination unit that determines screen information to be shared between the first terminal and the second terminal at a second time after the first time from the first screen information and the second screen information based on the first similarity and the elapsed time since the most recent user input to the first terminal; and a transfer unit that transfers the determined screen information to the second terminal.

2. The screen sharing device of claim 1, wherein the determination unit determines that the first screen information is screen information to be shared between the first terminal and the second terminal at the second time when the first similarity is equal to or greater than a first threshold, or when the first similarity is less than the first threshold and the elapsed time is equal to or greater than a second threshold, and determines that the second screen information is screen information to be shared between the first terminal and the second terminal at the second time when the first similarity is less than the first threshold and the elapsed time is less than the second threshold.

3. The screen sharing device according to claim 2, wherein the second threshold is dynamically determined based on a statistic of the elapsed time.

4. A screen sharing device as described in claim 1, wherein the calculation unit further calculates a second similarity between the first screen information and third screen information generated by the first terminal at a time different from the time when the second screen information was generated, and the determination unit determines the screen information to be shared between the first terminal and the second terminal at the second time based on the higher of the first similarity and the second similarity and the elapsed time.

5. The screen sharing device according to claim 2, wherein the user input includes key presses and mouse clicks detected on the first terminal.

6. A screen sharing device as described in claim 5, wherein the determination unit further determines that the second screen information is screen information to be shared between the first terminal and the second terminal at the second time when the first similarity is less than the first threshold, the elapsed time is equal to or greater than the second threshold, and a mouse is being dragged on the first terminal.

7. A screen sharing method comprising: calculating a first similarity between first screen information shared between a first terminal and a second terminal at a first time and second screen information generated by the first terminal after the first time; determining, based on the first similarity and an elapsed time from a most recent user input to the first terminal, screen information to be shared between the first terminal and the second terminal at a second time after the first time from the first screen information and the second screen information; and transferring the determined screen information to the second terminal.

8. A program for causing a computer to function as each unit of the screen sharing device according to any one of claims 1 to 6.

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