DEVICE SERVER, CLIENT APPARATUS, DEVICE SERVER SYSTEM, CONNECTION METHOD AND PROGRAM

Abstract

To provide a device server capable of switching a client apparatus connected to a device, in a different network segment.SOLUTION: A device server 30 includes a communication unit 32, and a control unit 31 that transmits and receives information to / from a plurality of client apparatuses via the communication unit 32. When receiving disconnection request information indicating a request to disconnect between a second client apparatus and a device from a first client apparatus while the second client apparatus is communicatively connected with the device, the control unit 31 transmits the disconnection request information to the second client apparatus. When receiving acceptance information indicating that the request to disconnect between the second client apparatus and the device has been accepted from the second client apparatus, the control unit disconnects between the second client apparatus and the device and communicatively connects the first client apparatus and the device.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a device server, a client device, a device server system, a connection method, and a program. [Background technology]

[0002] In recent years, devices called device servers have become widespread (see, for example, Patent Document 1). A device server is a device that connects computer peripherals (hereinafter also referred to as devices) such as an MFP (Multi Function Peripheral), a scanner, or a terrestrial digital tuner that are locally connected (hereinafter also referred to as simply connected) to itself via a USB (Universal Serial Bus) to a network, and allows a plurality of client devices (for example, PCs or tablets) to use these devices via the network.

[0003] Due to the USB specifications, while one of multiple client devices is communicatively connected to a device via the device server, the device server cannot connect another client device to the device. When a client device that was communicatively connected to a device is disconnected from the device, the device becomes connectable to another client device.

[0004] In response to this, there is a demand for one user to use multiple client devices and use the devices via a device server. For example, when a user is watching terrestrial digital broadcasting on a PC installed in one place, the user moves to another place and wants to continue watching the terrestrial digital broadcasting on a PC installed in the other place. In this case, it is necessary to disconnect the client device connected to the device and then connect the device to another client device. In Patent Document 1, the other client device directly requests a disconnection to the client device connected to the device, thereby disconnecting the client device and the device, and switching the client device connected to the device. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2016-162110 A Summary of the Invention [Problem to be solved by the invention]

[0006] In the above Patent Document 1, it is assumed that the client device connected to the device is switched in the same network segment, but there is a demand for switching the client device connected to the device not only for one user but also for client devices in different network segments. However, in different network segments, there is no communication path for direct communication between client devices in different network segments, and it is difficult for another client device to directly send a disconnection request to the client device connected to the device.

[0007] The present invention has been made to solve the above problems, and has an object to provide a device server or the like that can switch between a client apparatus connected to a device in different network segments. [Means for solving the problem]

[0008] In order to solve the above problem, a device server according to one aspect of the present invention is a device server in a device server system including a plurality of client devices including a first client device and a second client device, and a device server to which a device is connected, and in which one of the plurality of client devices is connected to the device so as to be able to communicate with the device via the device server, the device server including a server communication unit that communicates with the plurality of client devices, a server control unit that transmits and receives information to and from the plurality of client devices via the server communication unit, and a server storage unit, and when the server control unit receives a query from the first client device and the second client device is connected to the device so as to be able to communicate with the device, the server sends to the first client device connection information indicating that the second client device is communicatively connected to the device, and when disconnection request information indicating a request to disconnect the connection between the second client device and the device is received from the first client device, the server stores the disconnection request information in the server storage unit; when an inquiry is received from the second client device and the disconnection request information is stored in the server storage unit, the server sends the disconnection request information to the second client device; and when acceptance information indicating that the request to disconnect the connection between the second client device and the device has been accepted is received from the second client device, the server disconnects the connection between the second client device and the device and connects the first client device and the device so as to be communicatively connected.

[0009] According to this, when the second client device is connected to the device so as to be able to communicate with the device, the device server receives a request from the first client device to disconnect the connection between the second client device and the device, and when the second client device accepts the request to disconnect the connection with the device, disconnects the connection between the second client device and the device and connects the first client device and the device so as to be able to communicate with each other. In other words, the first client device can make a disconnection request to the second client device via the device server without making a disconnection request directly to the second client device, so that even if the network segment to which the first client device belongs and the network segment to which the second client device belongs are different, the first client device can make a disconnection request to the second client device via the device server. In this way, it is possible to switch the client device connected to the device in different network segments.

[0010] For example, the server control unit may transmit the connection information to the first client device by including in the connection information an address of the device server in a network segment to which the device server belongs.

[0011] According to this, when the address of the device server included in the connection information is different from the address of the device server used for communication with the device server, the first client device can determine that the network segment to which the first client device belongs is different from the network segment to which the device server belongs. When the network segment to which the first client device belongs is different from the network segment to which the device server belongs, it is highly likely that the network segment to which the first client device belongs is different from the network segment to which the second client device belongs. Therefore, in this case, the first client device can decide to make a disconnection request to the second client device via the device server.

[0012] For example, when the network segment to which the second client device belongs is different from the network segment to which the device server belongs, the server control unit may transmit the connection information to the first client device, including information indicating that the network segment to which the second client device belongs is different from the network segment to which the device server belongs. Specifically, the server control unit may transmit information including an address in the network segment to which the device server belongs to the second client device, and the information indicating that the network segment to which the second client device belongs is different from the network segment to which the device server belongs may be based on information transmitted from the second client device.

[0013] According to this, when the connection information includes information indicating that the network segment to which the second client device belongs is different from the network segment to which the device server belongs, it is highly likely that the network segment to which the first client device belongs is different from the network segment to which the second client device belongs, and therefore, in this case, the first client device can decide to make a disconnection request to the second client device via the device server.

[0014] For example, when the network segment to which the second client device belongs is different from the network segment to which the first client device belongs, the server control unit may send the connection information to the first client device, including information indicating that the network segment to which the second client device belongs is different from the network segment to which the first client device belongs.

[0015] According to this, if the connection information includes information indicating that the network segment to which the second client device belongs is different from the network segment to which the first client device belongs, the first client device can decide to make a disconnection request to the second client device via the device server.

[0016] In order to solve the above problem, a client device according to one embodiment of the present invention comprises a plurality of client devices including a first client device and a second client device, and a device server to which a device is connected, and is the first client device in a device server system in which one of the plurality of client devices is communicatively connected to the device via the device server, and comprises a client communication unit that communicates with the device server, and a client control unit that transmits and receives information with the device server via the client communication unit, wherein the client control unit transmits an inquiry to the device server, and when connection information indicating that the second client device is communicatively connected to the device is received from the device server in response to the inquiry, the client control unit transmits disconnection request information to the device server indicating a request to disconnect the connection between the second client device and the device, and when acceptance information indicating that the request to disconnect the connection between the second client device and the device has been accepted from the device server, the client control unit transmits connection request information to the device server indicating a request to communicatively connect the first client device and the device.

[0017] According to this, when the second client device is connected to the device so as to be able to communicate with the device, the client device (first client device) requests the device server to disconnect the second client device from the device, and when the second client device accepts the request to disconnect the device, the client device requests the device server to connect the client device to the device so as to be able to communicate with the device. In other words, the client device can make a disconnection request to the second client device via the device server without making a disconnection request directly to the second client device, so that even if the network segment to which the client device belongs is different from the network segment to which the second client device belongs, the client device can make a disconnection request to the second client device via the device server. In this way, it is possible to switch the client device connected to the device in different network segments.

[0018] For example, the client control unit may receive the connection information from the device server, and when a predetermined condition is satisfied, transmit the disconnection request information to the device server.

[0019] According to this, the client device does not always have to send a disconnection request to the second client device via the device server, and may send a disconnection request to the second client device via the device server only when a predetermined condition is satisfied. When the client device does not satisfy the predetermined condition (when the client device can send a disconnection request directly to the second client device), the client device can get a quicker response to the disconnection request by sending a disconnection request directly to the second client device.

[0020] For example, when the specified condition is met, the address of the device server in the network segment to which the device server belongs, which is included in the connection information, may be different from the address used for communication between the client device and the device server.

[0021] According to this, when the address of the device server included in the connection information is different from the address of the device server used for communication with the device server, the client device can determine that the network segment to which the client device (own device) belongs is different from the network segment to which the device server belongs. When the network segment to which the client device belongs is different from the network segment to which the device server belongs, it is highly likely that the network segment to which the client device (own device) belongs is different from the network segment to which the second client device belongs. Therefore, in this case, the client device can decide to make a disconnection request to the second client device via the device server.

[0022] For example, if the specified condition is met, the connection information may include information indicating that the network segment to which the second client device belongs is different from the network segment to which the device server belongs.

[0023] According to this, when the connection information includes information indicating that the network segment to which the second client device belongs is different from the network segment to which the device server belongs, it is highly likely that the network segment to which the client device (own device) belongs is different from the network segment to which the second client device belongs. Therefore, in this case, the client device can decide to make a disconnection request to the second client device via the device server.

[0024] For example, if the specified condition is met, the connection information may include information indicating that the network segment to which the second client device belongs is different from the network segment to which the first client device belongs.

[0025] According to this, if the connection information includes information indicating that the network segment to which the second client device belongs is different from the network segment to which the client device belongs, the client device can decide to make a disconnection request to the second client device via the device server.

[0026] In order to solve the above problem, a client device according to one embodiment of the present invention is a client device in a device server system comprising a plurality of client devices and a device server to which a device is connected, and which connects one of the plurality of client devices to the device so that it can communicate with the device via the device server, and which comprises a client communication unit that communicates with the device server, and a client control unit that transmits and receives information with the device server via the client communication unit, and the client control unit receives information from the device server including an address of the device server in a network segment to which the device server belongs, and if the address of the device server in the network segment to which the device server belongs, included in the information, is different from the address used for communication between the client device and the device server, transmits to the device server a message to the effect that the network segment to which the device server belongs and the network segment to which the client device belongs are different.

[0027] According to this, information indicating that the address of the device server in the network segment to which the device server belongs is different from the address used for communication between the client device and the device server can be used when switching between client devices connected to devices in different network segments, thereby enabling smooth switching between client devices connected to devices in different network segments.

[0028] In order to solve the above problem, a device server system according to one aspect of the present invention includes the above device server and the above client device.

[0029] This makes it possible to provide a device server system capable of switching between client apparatuses connected to devices in different network segments.

[0030] In order to solve the above problem, a connection method according to one aspect of the present invention is a connection method performed by a device server in a device server system, the device server including a plurality of client devices including a first client device and a second client device, and a device server to which a device is connected, the device server connecting one of the plurality of client devices to the device so as to be communicable with the device via the device server, the connection method including the steps of: when the second client device is communicably connected to the device and, upon receiving an inquiry from the first client device, transmitting connection information indicating that the second client device is communicably connected to the device to the first client device; The method includes the steps of: when receiving disconnection request information from the first client device, storing the disconnection request information in a server memory unit of the device server; when receiving an inquiry from the second client device, and the disconnection request information is stored in the server memory unit, transmitting the disconnection request information to the second client device; and when receiving acceptance information from the second client device, indicating that the request to disconnect the connection between the second client device and the device has been accepted, disconnecting the connection between the second client device and the device and connecting the first client device and the device so that they can communicate with each other.

[0031] This makes it possible to provide a connection method that allows switching of a client apparatus connected to a device in different network segments.

[0032] In order to solve the above problem, a program according to one aspect of the present invention is a program for causing a computer to execute the above connection method.

[0033] This makes it possible to provide a program that can switch between client apparatuses connected to devices in different network segments.

[0034] In order to solve the above problem, a connection method according to one aspect of the present invention is a connection method performed by a first client device in a device server system comprising a plurality of client devices including a first client device and a second client device, and a device server to which a device is connected, and in which one of the plurality of client devices is communicatively connected to the device via the device server, the connection method including the steps of: sending a query to the device server; when connection information indicating that the second client device is communicatively connected to the device is received from the device server in response to the query, sending to the device server disconnection request information indicating a request to disconnect the connection between the second client device and the device; and when acceptance information indicating that the request to disconnect the connection between the second client device and the device has been accepted is received from the device server, sending to the device server connection request information indicating a request to communicatively connect the first client device and the device.

[0035] This makes it possible to provide a connection method that allows switching of a client apparatus connected to a device in different network segments.

[0036] In order to solve the above problem, a program according to one aspect of the present invention is a program for causing a computer to execute the above connection method.

[0037] This makes it possible to provide a program that can switch between client apparatuses connected to devices in different network segments. Effect of the Invention

[0038] According to the present invention, it is possible to switch between client devices connected to devices in different network segments. [Brief description of the drawings]

[0039] [Figure 1] 1 is a configuration diagram showing a first example of a device server system according to a first embodiment. [Diagram 2] FIG. 2 is a configuration diagram illustrating an example of a client device according to the first embodiment. [Diagram 3] 2 is a configuration diagram illustrating an example of a device server according to the first embodiment. FIG. [Figure 4] 4 is a sequence diagram showing a first example of the operation of the device server system according to the first embodiment. FIG. [Diagram 5] FIG. 4 is a configuration diagram showing a second example of the device server system according to the first embodiment. [Figure 6] FIG. 11 is a sequence diagram showing a second example of the operation of the device server system according to the first embodiment. [Figure 7] FIG. 11 is a configuration diagram showing a third example of the device server system according to the first embodiment. [Figure 8] FIG. 11 is a configuration diagram illustrating an example of a device server system according to a second embodiment. [Figure 9] FIG. 11 is a sequence diagram showing an example of an operation of the device server system according to the second embodiment. [Figure 10] 13 is a flowchart showing an example of a connection method according to another embodiment. [Figure 11] 13 is a flowchart showing another example of a connection method according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0040] Hereinafter, the embodiment will be specifically described with reference to the drawings.

[0041] The embodiments described below each show a preferred specific example of the present invention. The numerical values, shapes, materials, components, the arrangement and connection of the components, steps, and the order of steps shown in the following embodiments are merely examples and are not intended to limit the present invention. Furthermore, among the components in the following embodiments, components that are not described in the independent claims are described as any components that constitute a more preferred embodiment. Note that the same reference numerals are used for the same components, and descriptions thereof may be omitted.

[0042] (Embodiment 1) The first embodiment will be described below with reference to FIGS. 1 to 7. FIG.

[0043] FIG. 1 is a configuration diagram showing a first example of a device server system 1 according to the first embodiment.

[0044] The device server system 1 is a system including a plurality of client devices including a first client device and a second client device, and a device server 30 to which a device 40 is connected. The device server system 1 connects one of the plurality of client devices to the device 40 via the device server 30 so as to be able to communicate with the device 40. In other words, while one of the plurality of client devices is connected to the device 40 via the device server 30 so as to be able to communicate with the device 40, the other client devices cannot connect to the device 40. When the connection between the client device that was connected to the device 40 so as to be able to communicate with the device 40 and the device 40 is disconnected, the device 40 becomes connectable from the other client devices.

[0045] Here, client devices 10 and 20 are shown as the multiple client devices. Note that the device server system 1 may include three or more client devices. Client device 10 is an example of a first client device, and client device 20 is an example of a second client device. The first client device is a client device that is about to be communicatively connected to device 40, and the second client device is a client device that has already been communicatively connected to device 40. Each of the multiple client devices can be either a first client device or a second client device depending on the connection state with device 40.

[0046] The device 40 is a computer peripheral device such as an MFP, a scanner, or a digital terrestrial tuner. The device 40 is connected to the device server 30 via, for example, a USB. Note that a plurality of devices 40 may be connected to the device server 30. For example, the client device 10 may be connected to a certain device 40 so as to be able to communicate with each other, and at the same time, the client device 20 may be connected to another device 40 so as to be able to communicate with each other.

[0047] In the first example shown in FIG. 1, the client device 10 belongs to a network segment 100, and the client device 20 and the device server 30 belong to a network segment 200. The network segments 100 and 200 are, for example, LANs (Local Area Networks). The network segments 100 and 200 are network segments with different IP address segments, and devices belonging to the network segment 100 communicate with devices belonging to the network segment 200 via the Internet. A modem or a router is provided in each network segment, and devices belonging to each network segment can be connected to the Internet via a modem or a router. When a device belonging to a certain network segment communicates with a device belonging to an external network segment, NAT (Network Address Translation) or NAPT (Network Address Port Translation) is performed in the modem and the router. That is, the address (e.g., IP address) of each device in each network segment is converted to another address when communicating with a device belonging to an external network segment.

[0048] Next, the configuration of the client device 10 will be described with reference to FIG.

[0049] 2 is a configuration diagram showing an example of the client device 10 according to the embodiment 1. Note that the client device 20 has the same components as the client device 10, so a description of the client device 20 will be omitted.

[0050] The client device 10 includes a control unit 11 and a communication unit 12. The client device 10 is a device such as a PC or a tablet, and has a function for using the device 40 via the device server 30. This function is realized, for example, by the control unit 11. The control unit 11 acquires information about the device 40 connected to the device server 30, and manages the device 40 from the client device 10. The control unit 11 allows the user to connect the client device 10 and a desired device 40 so as to be able to communicate with each other, or to disconnect the device 40 that is currently connected, and the user can use the device 40 connected via the device server 30 as if it were directly connected to the client device 10. Specifically, for example, this function is realized by an application (a virtual connection tool) provided in the client device 10.

[0051] The client device 10 is a computer including a processor, a memory, a communication interface, etc. The memory is a ROM (Read Only Memory) and a RAM (Random Access Memory), etc., and can store a program executed by the processor. The control unit 11 is realized by a processor or the like that executes a program stored in the memory. The communication unit 12 is realized by a communication interface, etc.

[0052] The communication unit 12 is an example of a client communication unit that communicates with the device server 30. The communication unit 12 communicates with the device server 30 in a wired or wireless manner.

[0053] The control unit 11 is an example of a client control unit that transmits and receives information to and from the device server 30 via the client communication unit. The control unit 11 periodically queries the device server 30, monitors the usage status of the device 40 (i.e., the connection status with multiple client devices), and acquires information indicating the usage status of the device 40 (hereinafter, may also be referred to as connection information). The control unit 11 also requests the device server 30 to connect or disconnect the client device 10 and the device 40. Details of the operation of the control unit 11 will be described later.

[0054] Although not shown, the client device 10 may include an application, a device driver, and a tunneling driver.

[0055] An application is software that is used by a user to provide instructions when the user wants device 40 to perform a particular task. For example, if device 40 is a scanner, an application would be software such as a scanner tool that comes with device 40 that receives direct instructions from the user to perform a scanner function.

[0056] A device driver is software for controlling the device 40, and is usually provided by the vendor of the device 40. An application such as a word processing software can use the device 40 via such a device driver.

[0057] The tunneling driver encapsulates an I / O request issued by the device driver to the device 40 into a network packet (also called a tunneling packet), and transmits it to the device server 30 via the communication unit 12. On the other hand, when the tunneling driver receives a tunneling packet including a response to the I / O request, it extracts (decapsulates) the response from the tunneling packet and passes it to the device driver.

[0058] Next, the configuration of the device server 30 will be described with reference to FIG.

[0059] FIG. 3 is a configuration diagram showing an example of the device server 30 according to the first embodiment.

[0060] The device server 30 includes a control unit 31, a communication unit 32, and a storage unit 33. The device server 30 is a device (computer) having a function for connecting a device 40 connected to itself via a USB to a network and for allowing a plurality of client devices to use the device 40 via the network. This function is realized by, for example, the control unit 31.

[0061] The device server 30 is a computer including a processor, a memory, a communication interface, a USB interface, etc. The memory is a ROM, a RAM, etc., and can store a program executed by the processor. The control unit 31 is realized by a processor or the like that executes a program stored in the memory. The communication unit 32 is realized by a communication interface, etc. The storage unit 33 is realized by a memory, but the memory in which the program is stored may be a memory separate from the storage unit 33. The USB interface is an interface that connects the device server 30 and the device 40.

[0062] The communication unit 32 is an example of a server communication unit that communicates with a plurality of client devices. The communication unit 32 communicates with the plurality of client devices in a wired or wireless manner.

[0063] The storage unit 33 is an example of a server storage unit. Disconnection request information is stored in the storage unit 33. The disconnection request information will be described later.

[0064] The control unit 31 is an example of a server control unit that transmits and receives information to and from a plurality of client devices via a server communication unit. The operation of the control unit 31 will be described in detail later.

[0065] Although not shown, the device server 30 may include a USB host controller and a tunneling driver.

[0066] The USB host controller is a device provided in the USB host side device, and manages input / output and the like of the device 40.

[0067] The tunneling driver is a driver that has the same functions as the tunneling driver in the client device 10 .

[0068] In the device server system 1, communication is performed between one of the multiple client devices and the device 40 by encapsulating and decapsulating data. Therefore, the one client device can theoretically use all the functions of the device via the network. However, since such communication does not use a protocol that specifies use in a network that allows exclusive control or simultaneous access on a file-by-file basis, such as NAS (Network Attached Storage), the device 40 can only be used from one client device at a time.

[0069] Next, a first example of the operation of the device server system 1 will be described with reference to FIG.

[0070] FIG. 4 is a sequence diagram showing a first example of the operation of the device server system 1 according to the first embodiment.

[0071] Note that the operations described below are mainly performed by client devices 10, 20 and device server 30, but each operation is basically performed by control unit 11 of client device 10, control unit 11 of client device 20, and control unit 31 of device server 30.

[0072] The client device 20 periodically inquires of the device server 30 about the usage status of the device 40, and the client device 20 transmits the inquiry to the device server 30 (step S101).

[0073] In response to the inquiry, the device server 30 transmits to the client device 20 connection information indicating that the device 40 is not communicably connected to any client device and that the device 40 is connectable (step S102).

[0074] The client device 20 transmits connection request information indicating a request to connect the client device 20 and the device 40 so that they can communicate with each other to the device server 30 (step S103). As a result, the device server 30 connects the client device 20 and the device 40 so that they can communicate with each other, and the user of the client device 20 starts using the device 40.

[0075] Meanwhile, the client device 10 also makes an inquiry to the device server 30 about the usage status of the device 40, and the client device 10 transmits the inquiry to the device server 30 (step S104).

[0076] When the device server 30 receives an inquiry from the client device 10 in a state where the client device 20 is communicatively connected to the device 40, the device server 30 transmits connection information indicating that the client device 20 is communicatively connected to the device 40 to the client device 10 as a response to the inquiry (step S105). At this time, the device server 30 transmits the connection information to the client device 10, including the address (e.g., IP address) of the device server 30 in the network segment 200 to which the device server 30 belongs.

[0077] Since the device 40 is already connected to the client device 20 so as to be able to communicate with the client device 10 and the client device 10 is currently unable to use the device 40, the client device 10 makes a request to disconnect the connection between the client device 20 and the device 40. At this time, the client device 10 determines whether to make the disconnection request between the client device 20 and the device 40 directly to the client device 20 or via the device server 30 (step S106). For example, if a predetermined condition is satisfied, the client device 10 determines to make the disconnection request via the device server 30, and if the predetermined condition is not satisfied, determines to make the disconnection request directly to the client device 20.

[0078] For example, in the situation of the first example, a case where a predetermined condition is satisfied is a case where the address of the device server 30 in the network segment 200 to which the device server 30 belongs, which is included in the connection information, is different from the address used for communication between the client device 10 and the device server 30. When the address of the device server 30 included in the connection information (the address notified in step S105) is different from the address of the device server 30 used for communication with the device server 30, the client device 10 can determine that the network segment 100 to which the client device 10 belongs is different from the network segment 200 to which the device server 30 belongs. When the address of the device server 30 in the network segment 200 to which the device server 30 belongs is different from the address used for communication between the client device 10 and the device server 30, the IP address of the device server 30 is converted by NAT or the like, and the network segment 100 to which the client device 10 belongs is different from the network segment 200 to which the device server 30 belongs. Therefore, in this case, the client device 10 can decide to make a disconnection request to the client device 20 via the device server 30.

[0079] When the client device 10 receives from the device server 30 connection information indicating that the client device 20 is connected to the device 40 so as to be able to communicate with the device 40 and determines that the above-mentioned predetermined condition is satisfied, the client device 10 transmits disconnection request information to the device server 30 (step S107). In other words, when the client device 10 receives the connection information from the device server 30 and the predetermined condition is satisfied, the client device 10 does not transmit the disconnection request information directly to the client device 20.

[0080] When the device server 30 receives, from the client device 10, disconnection request information indicating a request to disconnect the connection between the client device 20 and the device 40, the device server 30 stores the disconnection request information in the storage unit 33 (step S108). For example, the disconnection request information includes information indicating which client device is requesting the client device 20 to disconnect in order to use which device 40.

[0081] As described above, the client device 20 periodically makes an inquiry to the device server 30, and the client device 20 transmits the inquiry to the device server 30 (step S109).

[0082] When the device server 30 receives an inquiry from the client device 20, if the disconnection request information is stored in the storage unit 33, the device server 30 transmits the disconnection request information to the client device 20. Specifically, the processes from step S110 to step S112 are performed.

[0083] The device server 30 transmits information to the client device 20 indicating that a disconnection request has been made to the client device 20 (step S110).

[0084] For example, the information received by the client device 20 in step S110 does not indicate which client device is requesting disconnection from the client device 20 in order to use which device 40, so the client device 20 requests disconnection request information from the device server 30 (step S111). For example, the client device 20 may be using multiple devices 40 (e.g., an MFP and a scanner) at the same time, and requests disconnection request information from the device server 30 to confirm which device 40 is requesting disconnection.

[0085] The device server 30 transmits the disconnection request information stored in the storage unit 33 to the client device 20 (step S112). This allows the client device 20 to check whether the client device 10 has requested the client device 20 to disconnect in order to use the device 40.

[0086] The client device 20 processes the disconnection request (step S113). Specifically, the client device 20 notifies the user of the client device 20 that the client device 10 has requested the client device 20 to disconnect the connection with the device 40 in order to use the device 40, and asks whether or not to accept the disconnection request. In the explanation of FIG. 4, for example, it is assumed that the user of the client device 20 has finished using the device 40 and has accepted the disconnection request.

[0087] The client device 20 transmits, to the device server 30, acceptance information indicating that the request to disconnect the connection between the client device 20 and the device 40 has been accepted (step S114).

[0088] When the device server 30 receives, from the client device 20, acceptance information indicating that the request to disconnect the client device 20 from the device 40 has been accepted, the device server 30 disconnects the client device 20 from the device 40 and connects the client device 20 to the device 40 so that they can communicate with each other. Specifically, the processes from step S115 to step S118 are performed.

[0089] As described above, the client device 10 periodically makes an inquiry to the device server 30, and the client device 10 transmits the inquiry to the device server 30 (step S115).

[0090] The device server 30 transmits to the client device 20 acceptance information indicating that the request to disconnect the connection between the client device 20 and the device 40 has been accepted (step S116).

[0091] The client device 20 transmits a request to disconnect the connection between the client device 20 and the device 40 to the device server 30 (step S117). In response to this, the device server 30 disconnects the connection between the client device 20 and the device 40.

[0092] When the client device 10 receives, from the device server 30, acceptance information indicating that the request to disconnect the client device 10 and the device 40 has been accepted (step S116), the client device 10 transmits, to the device server 30, connection request information indicating a request to connect the client device 10 and the device 40 so that they can communicate with each other (step S118). As a result, the device server 30 connects the client device 10 and the device 40 so that they can communicate with each other.

[0093] Note that step S117 may be performed before step S115, or a request to disconnect the connection between the client apparatus 20 and the device 40 may be sent to the device server 30 in step S114.

[0094] In addition, in step S111, the client device 20 has been described as requesting disconnection request information from the device server 30, but for example, when the device server 30 receives an inquiry from the client device 20 (step S109), if the client device 20 that made the inquiry matches the client device that is the target of the disconnection request included in the disconnection request information, the device server 30 may itself respond with the disconnection request information to the client device 20 that made the inquiry. In this case, the processes of steps S110 and S111 can be omitted.

[0095] 1 and 4, a first example has been described in which the client device 10 and the device server 30 belong to the same network segment 200 and different network segments when the client device 10 wishes to connect to the device 40 via the device server 30 so as to be able to communicate with each other. Next, Figs. 5 and 6 will be used to explain a second example in which the client device 10 and the device server 30 belong to different network segments and the client device 10 and the device server 30 belong to the same network segment when the client device 10 wishes to connect to the device 40 via the device server 30 so as to be able to communicate with each other.

[0096] FIG. 5 is a configuration diagram showing a second example of the device server system 1 according to the first embodiment.

[0097] In the second example shown in FIG. 5, the client device 10 and the device server 30 are connected to a network segment 100a, and the client device 20 is connected to a network segment 200a.

[0098] A second example of the operation of the device server system 1 will be described with reference to FIG.

[0099] FIG. 6 is a sequence diagram showing a second example of the operation of the device server system 1 according to the first embodiment.

[0100] Note that the operations described below are mainly performed by client devices 10, 20 and device server 30, but each operation is basically performed by control unit 11 of client device 10, control unit 11 of client device 20, and control unit 31 of device server 30.

[0101] The client device 20 makes an inquiry to the device server 30 about the usage status of the device 40 based on a user instruction (a desire to use the device 40) or periodically, and the client device 20 sends an inquiry to the device server 30 (step S201).

[0102] In response to the inquiry, the device server 30 transmits connection information to the client device 20 indicating that the device 40 is not communicatively connected to any client device and is connectable to the device 40 (step S202). At this time, the device server 30 transmits the connection information to the client device 20, including the address (e.g., IP address) of the device server 30 in the network segment 100a to which the device server 30 belongs.

[0103] The client device 20 determines whether the network segment 200a to which the client device 20 belongs and the network segment 100a to which the device server 30 belongs are different network segments (step S203). If the address of the device server 30 included in the connection information (the address notified in step S202) is different from the address of the device server 30 used for communication with the device server 30, the client device 20 can determine that the network segment 200a to which the client device 20 belongs and the network segment 100a to which the device server 30 belongs are different. If the address of the device server 30 in the network segment 100a to which the device server 30 belongs is different from the address used for communication between the client device 20 and the device server 30, the IP address of the device server 30 is converted by NAT or the like, and the network segment 200a to which the client device 20 belongs and the network segment 100a to which the device server 30 belongs are different.

[0104] The client device 20 transmits connection request information to the device server 30, indicating a request to communicatively connect the client device 20 and the device 40 (step S204). At this time, the client device 20 transmits to the device server 30, the connection request information including information indicating that the network segment 200a to which the client device 20 belongs is different from the network segment 100a to which the device server 30 belongs. As a result, the device server 30 recognizes that the client device 20 and the device 40 are communicatively connected, and that the network segment 200a to which the client device 20 belongs is different from the network segment 100a to which the device server 30 belongs.

[0105] On the other hand, the client device 10 periodically inquires of the device server 30 about the usage status of the device 40, and the client device 10 transmits the inquiry to the device server 30 (step S205).

[0106] When the device server 30 receives an inquiry from the client device 10 in a state in which the client device 20 is communicatively connected to the device 40, the device server 30 transmits connection information indicating that the client device 20 is communicatively connected to the device 40 to the client device 10 as a response to the inquiry (step S206). At this time, if the network segment 200a to which the client device 20 belongs is different from the network segment 100a to which the device server 30 belongs, the device server 30 transmits the connection information to the client device 10, including information indicating that the network segment 200a to which the client device 20 belongs is different from the network segment 100a to which the device server 30 belongs. The information indicating that the network segment 200a to which the client device 20 belongs is different from the network segment 100a to which the device server 30 belongs is based on the information transmitted from the client device 20 (the information transmitted in step S204).

[0107] Since the device 40 is already connected to the client device 20 so as to be able to communicate with the client device 10 and the client device 10 is currently unable to use the device 40, the client device 10 makes a request to disconnect the connection between the client device 20 and the device 40. At this time, the client device 10 determines whether to make the disconnection request between the client device 20 and the device 40 directly to the client device 20 or via the device server 30 (step S207). For example, if a predetermined condition is satisfied, the client device 10 determines to make the disconnection request via the device server 30, and if the predetermined condition is not satisfied, determines to make the disconnection request directly to the client device 20.

[0108] For example, in the situation of the second example, a case where a predetermined condition is satisfied is a case where the connection information includes information indicating that the network segment 200a to which the client device 20 belongs is different from the network segment 100a to which the device server 30 belongs. When the connection information includes information indicating that the network segment 200a to which the client device 20 belongs is different from the network segment 100a to which the device server 30 belongs, if the client device 10 and the device server 30 belong to the same segment, the network segment 100a to which the client device 10 belongs is different from the network segment 200a to which the client device 20 belongs. Therefore, in this case, the client device 10 can decide to make a disconnection request to the client device 20 via the device server 30.

[0109] The processing from step S208 to step S219 is basically the same as the processing from step S107 to step S118 described in the first example, and therefore a description thereof will be omitted.

[0110] 1, 4, 5, and 6 have been described with reference to examples in which the client devices 10 and 20 belong to different network segments. In FIG. 7, which will be described next, a third example in which the client devices 10 and 20 belong to the same network segment and the device server 30 also belongs to the same network segment will be described with reference to FIG. 4, which has been used to describe the first example.

[0111] FIG. 7 is a configuration diagram showing a third example of the device server system 1 according to the first embodiment.

[0112] In a third example shown in FIG. 7, the client devices 10 and 20 and the device server 30 are connected to the same network segment 300 .

[0113] In the third example, the address (e.g., IP address) of the device server 30 in the network segment 200 to which the device server 30 belongs, which is included in the connection information in step S105 of FIG. 4 described in the first example, is the same as the address used for communication between the client device 10 and the device server 30. That is, this is because the client device 10 and the device server 30 are connected to the same network segment 300. For this reason, in step S106 of FIG. 4 described in the first example, it is determined that the predetermined condition is not satisfied and that a disconnection request is to be made directly to the client device 20. Thus, in the third example, the client device 10 makes a disconnection request directly to the client device 20 without going through the device server 30. Specifically, for example, the function (the function of making a disconnection request directly to the target client device) can be realized by an application (a virtual connection tool) provided in the client devices 10 and 20. When the predetermined condition is not satisfied (when a disconnection request can be made directly to the client device 20), the client device 10 can quickly obtain a response to the disconnection request by making a disconnection request directly to the client device 20.

[0114] As described above, when the above-mentioned predetermined conditions are satisfied, the client device 20 is communicably connected to the device 40, and when the device server 30 receives a request from the client device 10 to disconnect the connection between the client device 20 and the device 40, the device server 30 transmits the request to the client device 20, and when the client device 20 accepts the request to disconnect the connection with the device 40, the device server 30 disconnects the connection between the client device 20 and the device 40 and connects the client device 10 and the device 40 to be able to communicate. In addition, when the above-mentioned predetermined conditions are satisfied, if the client device 20 is communicably connected to the device 40, the client device 10 requests the device server 30 to disconnect the connection between the client device 20 and the device 40, and when the client device 20 accepts the request to disconnect the connection with the device 40, the device server 30 requests the client device 10 (its own device) to connect the client device 10 (its own device) to the device 40 to be able to communicate. That is, since the client device 10 can make a disconnection request to the client device 20 via the device server 30 without making a disconnection request directly to the client device 20, even if the network segment to which the client device 10 belongs is different from the network segment to which the client device 20 belongs, the client device 10 can make a disconnection request to the client device 20 via the device server 30. In this way, it is possible to switch the client device connected to the device 40 in different network segments. This can be applied, for example, when the client device 20 is connected to the device 40 via the device server 30 so as to be able to communicate with the device 40, and the client device 10 wants to use the device 40 via the Internet.

[0115] (Embodiment 2) For example, the device server may have a function for connecting to a plurality of different network segments, which will be described with reference to FIGS.

[0116] FIG. 8 is a configuration diagram showing an example of a device server system 2 according to the second embodiment.

[0117] The device server system 2 is a system including a plurality of client devices including a first client device and a second client device, and a device server 30a to which a device 40 is connected. The device server system 2 connects one of the plurality of client devices to the device 40 via the device server 30a so as to be able to communicate with the device 40. In other words, while one of the plurality of client devices is connected to the device 40 via the device server 30a so as to be able to communicate with the device 40, other client devices cannot connect to the device 40. When a connection between a client device that was connected to the device 40 so as to be able to communicate with the device 40 and the device 40 is disconnected, the device 40 becomes connectable from other client devices.

[0118] Here, client devices 10 and 20 are shown as multiple client devices. The device server system 2 may include three or more client devices. The client device 10 is an example of a first client device, and the client device 20 is an example of a second client device.

[0119] 8, the client device 10 belongs to the network segment 100b, the client device 20 belongs to the network segment 200b, and the device server 30a belongs to the network segments 100b and 200b. For example, the network segment 100b is a wireless LAN, the network segment 200b is a wired LAN, and the device server 30a has a function of connecting to both the wireless LAN and the wired LAN.

[0120] The components of the device server 30a are basically the same as those of the device server 30, so a description thereof will be omitted, but the device server 30a includes a communication unit (communication interface) for communicating with the client device 10 connected to the network segment 100b, and a communication unit (communication interface) for communicating with the client device 20 connected to the network segment 200b. The device server 30a may also include three or more communication units (communication interfaces). In this case, different network segments corresponding to each communication unit may be assigned.

[0121] Next, an example of the operation of the device server system 2 will be described with reference to FIG.

[0122] FIG. 9 is a sequence diagram showing an example of the operation of the device server system 2 according to the second embodiment.

[0123] Note that the operations described below are mainly performed by the client devices 10 and 20 and the device server 30a, but each operation is basically performed by the control unit 11 of the client device 10, the control unit 11 of the client device 20, and the control unit 31 of the device server 30a.

[0124] The client device 20 periodically inquires of the device server 30a about the usage status of the device 40, and the client device 20 transmits the inquiry to the device server 30a (step S301).

[0125] In response to the inquiry, the device server 30a transmits to the client device 20 connection information indicating that the device 40 is not communicably connected to any client device and that the device 40 is connectable (step S302).

[0126] The client device 20 transmits to the device server 30a connection request information based on a user instruction (a desire to use the device 40) or indicating a request to connect the client device 20 and the device 40 so that they can communicate with each other (step S303). As a result, the device server 30a connects the client device 20 and the device 40 so that they can communicate with each other.

[0127] The client device 10 makes an inquiry to the device server 30a about the usage status of the device 40 based on a user instruction (a desire to use the device 40) or periodically, and the client device 10 sends the inquiry to the device server 30a (step S304).

[0128] The device server 30a determines whether the network segment 200b to which the client device 20 communicatively connected to the device 40 belongs is different from the network segment 100b to which the inquiring client device 10 belongs (step S305). In this example, the device server 30a can determine the network segment to which each client device is connected, and therefore can make the determination in step S305.

[0129] When the device server 30a receives an inquiry from the client device 10 in a state in which the client device 20 is communicatively connected to the device 40, the device server 30a transmits connection information indicating that the client device 20 is communicatively connected to the device 40 to the client device 10 as a response to the inquiry (step S306). At this time, if the network segment 200b to which the client device 20 belongs is different from the network segment 100b to which the client device 10 belongs, the device server 30a transmits the connection information to the client device 10, including information indicating that the network segment 200b to which the client device 20 belongs is different from the network segment 100b to which the client device 10 belongs.

[0130] Next, since the device 40 is already connected to the client device 20 and the client device 10 is currently unable to use the device 40, the client device 10 makes a request to disconnect the connection between the client device 20 and the device 40. At this time, the client device 10 determines whether to make the disconnection request between the client device 20 and the device 40 directly to the client device 20 or via the device server 30a (step S307). For example, if a predetermined condition is met, the client device 10 determines to make the disconnection request via the device server 30a, and if the predetermined condition is not met, determines to make the disconnection request directly to the client device 20.

[0131] For example, a case where a predetermined condition is satisfied is when the connection information includes information indicating that the network segment 200b to which the client device 20 belongs is different from the network segment 100b to which the client device 10 belongs. In this case, the client device 10 can decide to make a disconnection request to the client device 20 via the device server 30a.

[0132] The processing from step S308 to step S319 is basically the same as the processing from step S107 to step S118 described in the first example of the first embodiment, and therefore a description thereof will be omitted.

[0133] In addition, in embodiment 2, if client device 10 and client device 20 belong to the same network segment, the predetermined condition is not satisfied in step S307, and it is determined that a disconnection request should be made directly to client device 20, and client device 10 makes the disconnection request directly to client device 20 without going through device server 30a.

[0134] In this way, the device server 30a may have a function for connecting to a plurality of different network segments, and even in this case, it is possible to switch between client apparatuses connected to the device 40 in different network segments.

[0135] (Other embodiments) Although the device server, client device, and device server system of the present invention have been described above based on the embodiments, the present invention is not limited to the above-mentioned embodiments. As long as they do not deviate from the spirit of the present invention, various modifications conceivable by those skilled in the art to the present embodiments and forms constructed by combining components of different embodiments are also included within the scope of the present invention.

[0136] For example, the present invention can be realized not only as a device server, but also as a connection method including steps (processing) performed by components (eg, control unit 31) that make up the device server.

[0137] FIG. 10 is a flowchart showing an example of a connection method according to another embodiment.

[0138] The connection method is a connection method performed by a device server in a device server system that includes a plurality of client devices including a first client device and a second client device, and a device server to which a device is connected, and that connects one of the plurality of client devices to the device via the device server so as to be communicable with the device, and includes the steps of: when the second client device is communicably connected to the device and an inquiry is received from the first client device, transmitting connection information indicating that the second client device is communicably connected to the device to the first client device (step S11); The method includes a step of storing the disconnection request information in a server memory section of the device server when disconnection request information indicating a request to disconnect the connection is received from the first client device (step S12); a step of transmitting the disconnection request information to the second client device when an inquiry is received from the second client device and the disconnection request information is stored in the server memory section (step S13); and a step of disconnecting the connection between the second client device and the device and connecting the first client device and the device so as to be able to communicate with each other when acceptance information indicating that the request to disconnect the connection between the second client device and the device has been accepted is received from the second client device (step S14).

[0139] Furthermore, for example, the present invention can be realized not only as a client device, but also as a connection method including steps (processing) performed by components (eg, control unit 11) that configure the client device.

[0140] FIG. 11 is a flowchart showing another example of a connection method according to another embodiment.

[0141] The connection method is a connection method performed by a first client device in a device server system comprising a plurality of client devices including a first client device and a second client device, and a device server to which the device is connected, and in which one of the plurality of client devices is communicatively connected to the device via the device server, and includes the steps of: sending a query to the device server (step S21); when connection information indicating that the second client device is communicatively connected to the device is received from the device server in response to the query, sending to the device server disconnection request information indicating a request to disconnect the connection between the second client device and the device (step S22); and when acceptance information indicating that the request to disconnect the connection between the second client device and the device has been accepted is received from the device server, sending to the device server connection request information indicating a request to communicatively connect the first client device and the device (step S23).

[0142] Also, for example, each step in each connection method may be executed by a computer (computer system).The present invention can be realized as a program for causing a computer to execute the steps included in these methods.Furthermore, the present invention can be realized as a non-transitory computer-readable recording medium, such as a CD-ROM, on which the program is recorded.

[0143] For example, when the present invention is realized by a program (software), each step is executed by executing the program using hardware resources such as a computer's CPU, memory, input / output circuits, etc. In other words, each step is executed by the CPU acquiring data from memory or input / output circuits, etc., performing calculations, and outputting the results of the calculations to memory or input / output circuits, etc.

[0144] Furthermore, each of the components included in the device server and the client device of the above-described embodiment may be realized as a dedicated or general-purpose circuit. These components may be realized as one circuit or as multiple circuits.

[0145] Furthermore, the multiple components included in the device server and client device of the above-described embodiment may be realized as an LSI (Large Scale Integration), which is an integrated circuit (IC). These components may be individually integrated into a single chip, or may be integrated into a single chip that includes some or all of the components. Depending on the degree of integration, the LSI may be called a system LSI, a super LSI, or an ultra LSI.

[0146] In addition, the integrated circuit is not limited to an LSI, and may be realized by a dedicated circuit or a general-purpose processor. As described above, a programmable FPGA or a reconfigurable processor in which the connections and settings of circuit cells in an LSI can be reconfigured may be used.

[0147] Furthermore, if an integrated circuit technology that can replace LSI emerges due to advances in semiconductor technology or other derived technologies, it is natural that each component included in the device server and client device may be integrated into an integrated circuit using that technology.

[0148] In addition, the present invention also includes forms obtained by applying various modifications to the embodiments that a person skilled in the art may conceive, and forms realized by arbitrarily combining the components and functions of each embodiment without departing from the spirit of the present invention. [Industrial Applicability]

[0149] The present invention can be used in a device server or the like that allows a plurality of client devices to use devices such as computer peripherals via a network. [Explanation of symbols]

[0150] 1, 2 Device Server System 10, 20 Client device 11, 31 Control section 12, 32 Communications Department 33 Storage section 30, 30a Device Server 40 Devices 100, 100a, 100b, 200, 200a, 200b, 300 network segments

Claims

1. A device server in a device server system including a plurality of client devices including a first client device and a second client device, and a device server to which devices are connected, the device server being configured to connect one of the plurality of client devices to the device server so as to be able to communicate with the device, a server communication unit that communicates with the plurality of client devices; a server control unit that transmits and receives information to and from the plurality of client devices via the server communication unit; A server storage unit, The server control unit When the second client device is communicatively connected to the device and an inquiry is received from the first client device, the second client device transmits connection information indicating that the second client device is communicatively connected to the device to the first client device; When disconnection request information indicating a request for disconnection between the second client apparatus and the device is received from the first client apparatus, the disconnection request information is stored in the server storage unit; When receiving an inquiry from the second client device, if the disconnection request information is stored in the server storage unit, transmitting the disconnection request information to the second client device; when receiving, from the second client device, acceptance information indicating that a request to disconnect the connection between the second client device and the device has been accepted, disconnecting the connection between the second client device and the device and connecting the first client device and the device so as to be able to communicate with each other; Device server.

2. the server control unit transmits the connection information to the first client device, the connection information including an address of the device server in a network segment to which the device server belongs; The device server of claim 1 .

3. the server control unit, when a network segment to which the second client device belongs is different from a network segment to which the device server belongs, transmits the connection information to the first client device, the connection information including information indicating that the network segment to which the second client device belongs is different from a network segment to which the device server belongs. The device server of claim 1 .

4. The server control unit Sending information to the second client device, the information including an address in a network segment to which the device server belongs; The information indicating that the network segment to which the second client device belongs is different from the network segment to which the device server belongs is based on information transmitted from the second client device. The device server of claim 3 .

5. When the network segment to which the second client device belongs is different from the network segment to which the first client device belongs, the server control unit transmits the connection information to the first client device, including information indicating that the network segment to which the second client device belongs is different from the network segment to which the first client device belongs, in the connection information. The device server of claim 1 .

6. A device server system includes a plurality of client devices including a first client device and a second client device, and a device server to which a device is connected, and the device server system connects one of the plurality of client devices to the device server so as to be communicable with the device, the client device being the first client device in the device server system, A client communication unit that communicates with the device server; a client control unit that transmits and receives information to and from the device server via the client communication unit; The client control unit Sending a query to the device server; receiving connection information from the device server as a response to the inquiry, the connection information indicating that the second client apparatus is communicatively connected to the device, and if a predetermined condition is satisfied, transmitting disconnection request information indicating a request to disconnect the connection between the second client apparatus and the device to the device server; when receiving acceptance information from the device server indicating that a request to disconnect the second client apparatus and the device has been accepted, transmitting connection request information to the device server indicating a request to connect the first client apparatus and the device so as to be able to communicate with each other; The predetermined condition is satisfied when an address of the device server in the network segment to which the device server belongs, which is included in the connection information, is different from an address used for communication between the client device and the device server. Client device.

7. A client device comprising a plurality of client devices including a first client device and a second client device, and a device server to which devices are connected, the client device being the first client device in a device server system in which one of the plurality of client devices is communicably connected to the device via the device server, A client communication unit that communicates with the device server; a client control unit that transmits and receives information to and from the device server via the client communication unit; The client control unit Sending a query to the device server; receiving connection information from the device server as a response to the inquiry, the connection information indicating that the second client apparatus is communicatively connected to the device, and if a predetermined condition is satisfied, transmitting disconnection request information indicating a request to disconnect the connection between the second client apparatus and the device to the device server; when receiving acceptance information from the device server indicating that a request to disconnect the second client apparatus and the device has been accepted, transmitting connection request information to the device server indicating a request to connect the first client apparatus and the device so as to be able to communicate with each other; When the predetermined condition is satisfied, the connection information includes information indicating that a network segment to which the second client device belongs is different from a network segment to which the device server belongs. Client device.

8. A client device comprising a plurality of client devices including a first client device and a second client device, and a device server to which devices are connected, the client device being the first client device in a device server system in which one of the plurality of client devices is communicably connected to the device via the device server, A client communication unit that communicates with the device server; a client control unit that transmits and receives information to and from the device server via the client communication unit; The client control unit Sending a query to the device server; receiving connection information from the device server as a response to the inquiry, the connection information indicating that the second client apparatus is communicatively connected to the device, and if a predetermined condition is satisfied, transmitting disconnection request information indicating a request to disconnect the connection between the second client apparatus and the device to the device server; when receiving acceptance information from the device server indicating that a request to disconnect the second client apparatus and the device has been accepted, transmitting connection request information to the device server indicating a request to connect the first client apparatus and the device so as to be able to communicate with each other; When the predetermined condition is satisfied, the connection information includes information indicating that a network segment to which the second client device belongs is different from a network segment to which the first client device belongs. Client device.

9. A device server system includes a plurality of client devices and a device server to which devices are connected, and connects one of the plurality of client devices to the device server so as to be able to communicate with the device, the device server comprising: A client communication unit that communicates with the device server; a client control unit that transmits and receives information to and from the device server via the client communication unit; The client control unit receiving information from the device server including an address of the device server in a network segment to which the device server belongs; if an address of the device server in the network segment to which the device server belongs, which is included in the information, is different from an address used for communication between the client device and the device server, transmitting to the device server a message indicating that the network segment to which the device server belongs is different from the network segment to which the client device belongs; Client device.

10. A device server according to any one of claims 1 to 5; A client device according to any one of claims 6 to 9, Device server system.

11. A connection method performed by a device server in a device server system, the device server including a plurality of client devices including a first client device and a second client device, and a device server to which a device is connected, the device server connecting one of the plurality of client devices to the device so as to be able to communicate with the device via the device server, the method comprising: When the second client device is communicatively connected to the device, upon receiving an inquiry from the first client device, transmitting connection information indicating that the second client device is communicatively connected to the device to the first client device; when disconnection request information indicating a request for disconnection between the second client apparatus and the device is received from the first client apparatus, storing the disconnection request information in a server storage unit of the device server; when receiving an inquiry from the second client device, if the disconnection request information is stored in the server storage unit, transmitting the disconnection request information to the second client device; when receiving acceptance information from the second client device indicating that a request to disconnect the connection between the second client device and the device has been accepted, disconnecting the connection between the second client device and the device and connecting the first client device and the device so as to be able to communicate with each other; How to connect:

12. A program for causing a computer to execute the connection method according to claim 11.

13. A connection method performed by a first client device in a device server system including a plurality of client devices including a first client device and a second client device, and a device server to which a device is connected, the device server system connecting one of the plurality of client devices to be communicable with the device via the device server, the method comprising: sending a query to the device server; receiving connection information from the device server as a response to the inquiry, the connection information indicating that the second client apparatus is communicatively connected to the device, and when a predetermined condition is satisfied, transmitting disconnection request information indicating a request to disconnect the connection between the second client apparatus and the device to the device server; when receiving acceptance information from the device server indicating that a request to disconnect the second client apparatus and the device has been accepted, transmitting connection request information indicating a request to communicatively connect the first client apparatus and the device to the device server; The predetermined condition is satisfied when an address of the device server in the network segment to which the device server belongs, which is included in the connection information, is different from an address used for communication between the client device and the device server. How to connect:

14. A connection method performed by a first client device in a device server system comprising a plurality of client devices including a first client device and a second client device, and a device server to which devices are connected, the device server being connected to one of the plurality of client devices so as to be communicable with the device via the device server, the method comprising: sending a query to the device server; receiving connection information from the device server as a response to the inquiry, the connection information indicating that the second client apparatus is communicatively connected to the device, and when a predetermined condition is satisfied, transmitting disconnection request information indicating a request to disconnect the connection between the second client apparatus and the device to the device server; when receiving acceptance information from the device server indicating that a request to disconnect the second client apparatus and the device has been accepted, transmitting connection request information indicating a request to communicatively connect the first client apparatus and the device to the device server; When the predetermined condition is satisfied, the connection information includes information indicating that a network segment to which the second client device belongs is different from a network segment to which the device server belongs. How to connect:

15. A connection method performed by a first client device in a device server system comprising a plurality of client devices including a first client device and a second client device, and a device server to which devices are connected, the device server being connected to one of the plurality of client devices so as to be communicable with the device via the device server, the method comprising: sending a query to the device server; receiving connection information from the device server as a response to the inquiry, the connection information indicating that the second client apparatus is communicatively connected to the device, and when a predetermined condition is satisfied, transmitting disconnection request information indicating a request to disconnect the connection between the second client apparatus and the device to the device server; when receiving acceptance information from the device server indicating that a request to disconnect the second client apparatus and the device has been accepted, transmitting connection request information indicating a request to communicatively connect the first client apparatus and the device to the device server; When the predetermined condition is satisfied, the connection information includes information indicating that a network segment to which the second client device belongs is different from a network segment to which the first client device belongs. How to connect:

16. A program for causing a computer to execute the connection method according to any one of claims 13 to 15.

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