Communication apparatus, state control method and program

Abstract

To reduce power consumption of an apparatus at time when communication is not performed in a communication apparatus that communicates with other apparatus through an USB interface.SOLUTION: A communication apparatus that is the communication apparatus which comprises an USB device having an USB interface, and can communicate with other apparatus through the USB interface comprises: an USB state management unit that manages an operational state of the USB device; a power supply state management unit that manages a power supply state of the communication apparatus; and a system control unit that performs state control processing to control transition of the communication apparatus to the power supply state having smaller power consumption than the present power supply state when an operational state, in which the USB device stops communication with the other apparatus, continues for predetermined time.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a communication device, a state control method, and a program. [Background technology]

[0002] There are devices that monitor a network port while in a power saving mode, and if the network is disconnected for a certain period of time, turn off the main power to reduce power consumption.

[0003] Furthermore, in order to prevent the power from being turned off and the user's usability from being impaired when a communication cable is unintentionally unplugged, a technology is known in which the connection and disconnection of communication with the other device is determined based on the power supply in the physical layer (see, for example, Patent Document 1). Summary of the Invention [Problem to be solved by the invention]

[0004] However, in conventional technologies such as those shown in Patent Document 1, when communication is occurring at the physical layer (e.g., around the power supply), there is a problem in that it is not possible to reduce the power consumption of the device by turning off the power of the device, even if communication is not occurring at a higher layer.

[0005] One embodiment of the present invention has been made in consideration of the above-mentioned problems, and reduces the power consumption of a communication device that communicates with other devices via a USB interface when communication is not taking place. [Means for solving the problem]

[0006] In order to solve the above problem, a communication device according to one embodiment of the present invention is a communication device equipped with a USB device having a USB interface and capable of communicating with other devices via the USB interface, and includes a USB state management unit that manages the operating state of the USB device, a power state management unit that manages the power state of the communication device, and a system control unit that executes a state control process that controls the transition of the communication device to a power state that consumes less power than its current power state when the operating state in which the USB device is suspending communication with the other device continues for a predetermined period of time. [Effects of the Invention]

[0007] According to one embodiment of the present invention, in a communication device that communicates with other devices via a USB interface, it is possible to reduce the power consumption of the communication device when no communication is taking place. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a communication system according to an embodiment. [Figure 2] FIG. 2 is a diagram illustrating an example of a functional configuration of a communication device according to an embodiment. [Figure 3] FIG. 2 is a diagram illustrating a layer configuration of USB communication. [Figure 4] FIG. 2 is a diagram illustrating the function layers of a USB device according to an embodiment. [Figure 5] FIG. 2 is a diagram illustrating an example of state transition of the communication device according to the first embodiment. [Figure 6] FIG. 4 is a diagram illustrating an example of state transition of a communication USB device according to the first embodiment. [Figure 7] FIG. 10 is a diagram (USB 2.0) for explaining the process of transitioning to a suspended state. [Figure 8] FIG. 10 is a diagram (USB 3.0) for explaining the process of transitioning to a suspended state. [Figure 9] 6 is a flowchart illustrating an example of a state control process according to the first embodiment. [Figure 10] FIG. 10 is a diagram illustrating an example of state transition of a communication device according to a second embodiment. [Figure 11] FIG. 10 is a diagram illustrating an example of state transition of a communication USB device according to the second embodiment. [Figure 12] 10 is a flowchart (1) illustrating an example of a state control process according to the second embodiment. [Figure 13] 10 is a flowchart (2) illustrating an example of a state control process according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0010] <System configuration> 1 is a diagram showing an example of the configuration of a communication system according to an embodiment. The communication system 1 includes a communication device 10 that includes a USB device having a USB interface and is capable of communicating with other devices having USB host functionality via the USB interface.

[0011] FIG. 1 illustrates an example of a hardware configuration in which the communication device 10 is an image forming device equipped with functions such as a printer, scanner, copier, and fax (facsimile). However, the communication device 10 may be an electronic device other than an image forming device having the functions of the USB device 100. For example, the communication device 10 may be an output device such as a PJ (Projector), an IWB (Interactive Whiteboard: a whiteboard with an electronic blackboard function that allows intercommunication), or a digital signage, or a HUD (Head Up Display) device. The communication device 10 may also be an industrial machine, an imaging device, a sound collection device, a medical device, a network home appliance, or an automobile (Connected Car). The communication device 10 may also be a notebook PC (Personal Computer), a mobile phone, a smartphone, a tablet terminal, a game console, a PDA (Personal Digital Assistant), a digital camera, a wearable PC, a desktop PC, or the like.

[0012] The information processing device 20 is a computer having a USB host function, such as a PC, a tablet terminal, or a smartphone. The information processing device 20 is an example of another device that can communicate with the communication device, and may be a device external to the communication system 1.

[0013] <Hardware configuration> In the example of Figure 1, the communication device 10 has a wired LAN (Local Area Network) I / F (Interface) 11, a wireless LAN module 12, a CPU (Central Processing Unit) 13, memory 14, a power supply 15, a printer 16, a scanner 17, a FAX 18, a USB device 100, and a bus B, etc.

[0014] The wired LAN I / F 11 is a communication interface for connecting the communication device 10 to a network via a communication cable such as a LAN cable, etc. The wireless LAN module 12 is a communication interface for connecting the communication device 10 to a network via wireless communication.

[0015] The CPU 13 is a processor (arithmetic unit) that controls the entire communication device 10 by executing a predetermined program stored in a storage medium such as the memory 14. The memory 14 includes, for example, a random access memory (RAM) that is a volatile memory used as a work area or the like for the CPU 13, and a read-only memory (ROM) that is a non-volatile memory that stores a startup program or the like in advance. The memory 14 may also include, for example, a storage device such as a hard disk drive (HDD) or a solid state drive (SSD).

[0016] The power supply 15 is a power supply circuit or a power supply system that supplies power to each part of the communication device 10. The printer 16 is a device that executes printing processing. The scanner 17 is a device that executes document reading processing. The FAX 18 is a device that executes fax sending and receiving processing. If the communication device 10 is, for example, a projector, the communication device 10 has an image projection device that executes image projection processing instead of the printer 16, the scanner 17, the FAX 18, etc.

[0017] The USB device 100 includes, for example, another communication device, a USB I / F (USB interface) 110 that transmits and receives data via USB communication, and a USB device controller that controls the USB communication via the USB I / F 110. A bus B is commonly connected to the above components and transmits, for example, address signals, data signals, and various control signals.

[0018] <Functional configuration> FIG. 2 is a diagram illustrating an example of a functional configuration of a communication device according to an embodiment.

[0019] (USB device functional configuration) The USB I / F 110 of the USB device 100 includes, for example, a receiving unit 111 and a transmitting unit 112. The receiving unit 111 executes a receiving process for receiving data from another device (information processing device 20) that is a USB host. The transmitting unit 112 executes a transmitting process for transmitting data to another device that is a USB host under the control of the USB device controller 120.

[0020] The USB device controller 120 has the configuration of a computer, for example, and executes a predetermined program to realize various functional components, such as an endpoint control unit 121, a USB status management unit 122, and a USB event management unit 123. Note that at least a portion of the above-described functional components may be realized by hardware.

[0021] The endpoint control unit 121 controls input and output of data to and from an endpoint, which is a FIFO (First In, First Out) buffer that stores data for USB communication. The endpoint control unit 121 also acquires information about the USB I / F 110 (for example, the connection status of the USB cable, etc.).

[0022] The USB state management unit 122 manages the operating state of the USB device 100. The operating states of the USB device 100 include, for example, a cable-unconnected state, an attached state, a powered state, a default state, an address state, a configured state, a suspended state, or a paused state. Each operating state and state transitions will be described later.

[0023] The USB event management unit 123 receives USB information from the endpoint control unit 121 and the USB state management unit 122, and notifies the communication event management unit 203. The USB event management unit 123 also receives a notification of an automatic transition OFF state, which will be described later, from the communication event management unit 203, and notifies the USB state management unit 122.

[0024] (Functional configuration of communication device) The communication device 10 executes a predetermined program stored in a storage medium such as the memory 14 to implement various functional components, such as a wired LAN event manager 201, a wireless LAN event manager 202, a communication event manager 203, a power status manager 204, a system controller 205, a timer controller 206, a main power manager 207, and a power saving manager 208. At least some of the functional components described above may be implemented by hardware.

[0025] The wired LAN event management unit 201 detects events such as a network connection or disconnection to the wired LAN I / F 11, and notifies the communication event management unit 203. The wireless LAN event management unit 202 detects events such as a network connection or disconnection to the wireless LAN module 12, and notifies the communication event management unit 203.

[0026] The communication event management unit 203 manages information about communication events notified from the USB event management unit 123, the wired LAN event management unit 201, the wireless LAN event management unit 202, etc. For example, the communication event management unit 203 manages USB information including the operating state of the USB device 100 and the connection state of the USB cable, etc., notified from the USB event management unit 123. The communication event management unit 203 also manages the connection state of the communication port, etc., notified from the wired LAN event management unit 201 and the wireless LAN event management unit 202.

[0027] The power state management unit 204 executes a power state management process for managing the power state of the communication device 10. The power states of the communication device 10 include, for example, a normal state, a power saving state, a main power off state, and an automatic transition off state. The normal state is a power state in which the communication device 10 is normally activated and is capable of executing predetermined functions of the communication device 10 (for example, printing, scanning, copying, faxing, etc.). The power saving state (first power saving state) is a power state in which some of the hardware of the communication device 10 is stopped and consumes less power than the normal state. In the power saving state, the communication device 10 may not be able to execute the predetermined functions described above.

[0028] The main power off state is a power state in which the communication device 10 is completely powered off. To return to the normal state from the main power off state, for example, it is necessary to press the main power button. The automatic transition off state (second power saving state) is a power state in which power consumption is lower than the power saving state, in which most of the communication device 10 is stopped, and only the minimum functions are operating. In the automatic transition off state, the device transitions to the power saving state when the insertion of a communication cable such as a USB cable or LAN cable is detected, and can transition to the normal state by pressing the main power button. Note that the automatic transition off state is optional and not required.

[0029] The system control unit 205 is a control unit that controls the entire communication device 10. For example, if the USB device 100 remains in an operating state where it is not communicating with other devices for a predetermined period of time, the system control unit 205 executes a state control process that controls the transition of the communication device 10 to a power state that consumes less power than the current power state. The "current power state" is the power state at the time the state control process is started.

[0030] Preferably, the system control unit 205 executes state control processing when a cable is connected to the USB I / F 110, when the current power state is a power saving state, or when communication interfaces such as wireless LAN and wired LAN are disabled.

[0031] The timer control unit 206 controls a timer that measures a predetermined time. The main power management unit 207 executes processes such as turning on and off the power of the entire device. The power saving management unit 208 executes processes such as transitioning the communication device 10 to a normal state, a power saving state, a main power off state, an automatic transition off state, etc.

[0032] 2 is an example. For example, at least some of the functions of the communication event management unit 203, the power state management unit 204, the timer control unit 206, the main power management unit 207, and the power saving management unit 208 may be included in the system control unit 205.

[0033] (USB communication layer structure) 3 is a diagram for explaining the layer structure of USB communication. A communication apparatus (USB device) 10 has a layer structure including a physical layer 301, a link layer 302, and a protocol layer 303. An information processing apparatus (USB host) 20 also has a similar layer structure.

[0034] The physical layer 301 is a layer that transmits and receives data in the form of electrical signals via a USB cable 304. The link layer 302 is a layer that controls communication between adjacent devices (for example, a USB host and a USB device). The protocol layer 303 is a layer that controls packets.

[0035] 4 is a diagram illustrating the functional layers of a USB device according to an embodiment. As shown in FIG. 4, the USB I / F 110 according to this embodiment corresponds to a physical layer 301, and the USB device controller 120 corresponds to a link layer 302.

[0036] [First embodiment] (State transition of communication device) 5 is a diagram showing an example of state transitions of the communication device 10 according to the first embodiment. The communication device 10 according to the first embodiment has three power states: a normal state 501, a power saving state 502, and a main power off state 503.

[0037] The normal state 501 is a power state in which the communication device 10 is normally activated and is capable of executing predetermined functions of the communication device 10. In the normal state 501, the communication device 10 transitions to a power saving state 502 by power saving state transition control, and transitions to a main power off state 503 by pressing the main power button.

[0038] The power saving state 502 is a power state in which some of the hardware included in the communication device 10 is stopped and consumes less power than the normal state 501. In the power saving state 502, the communication device 10 transitions to the normal state 501 by recovery control from the power saving state 502. Also, in the power saving state 502, the communication device 10 transitions to the main power off state 503 when the USB device 100 is in a suspended state and the wired LAN port and the wireless LAN port are disabled.

[0039] The main power off state 503 is a power state in which the power of the communication device 10 is completely turned off. In the main power off state 503, the communication device 10 transitions to the normal state 501 when the main power button is pressed.

[0040] (USB device state transition) 6 is a diagram showing an example of state transitions of a USB device according to the first embodiment. The USB device 100 according to the first embodiment has operating states such as a cable unconnected state 601, an attached state 602, a powered state 603, a default state 604, an address state 605, a configured state 606, and a suspended state 607.

[0041] The cable unconnected state 601 is an operating state in which no cable is connected to the USB I / F 110. In the cable unconnected state 601, the USB device 100 transitions to an attached state 602 when a cable is inserted. The attached state 602 is a state in which a cable is connected to the USB I / F 110 but power is not being applied. In the attached state 602, the USB device 100 transitions to a powered state 603 when power is applied, and transitions to the cable unconnected state 601 when the cable is removed.

[0042] The POWERED state 603 is a state in which the cable is connected and power is applied, but communication is not yet possible. In the POWERED state 603, the USB device 100 transitions to the DEFAULT state 604 once configuration is complete. The DEFAULT state 604 is a state in which the cable is connected, power is applied, and communication is possible, but no address has been assigned. In the DEFAULT state 604, the USB device 100 transitions to the ADDRESS state 605 in response to a SET_ADDRESS command, and transitions to the POWERED state 603 in response to a BUS reset.

[0043] The ADDRESS state 605 is a state in which the cable is connected, power is applied, communication is possible, an address is assigned, but the device is not configured (not yet usable). In the ADDRESS state 605, the USB device 100 transitions to the CONFIGURED state (usable state) 606 in response to a SET_CONFIGURATION command, and transitions to the POWERED state 603 in response to a BUS reset. The CONFIGURED state 606 is a state in which power is applied, communication is possible, an address is assigned, and the device is configured. In the CONFIGURED state 606, the USB device 100 transitions to the POWERED state 603 in response to a BUS reset.

[0044] The SUSPEND state 607 is a state in which the USB device 100 and the bus are in low power. The USB device 100 can transition to the SUSPEND state 607 from the POWERED state 603, DEFAULT state 604, ADDRESS state 605, and CONFIGURED state 606.

[0045] In USB 2.0, if the USB device 100 detects no bus activity for 3 ms or more in the POWERED state 603, DEFAULT state 604, ADDRESS state 605, or CONFIGURED state 606, it transitions to the SUSPEND state 607.

[0046] 7 is a diagram (USB 2.0) for explaining an example of the process of transitioning to a suspended state. For example, in step S701, it is assumed that the information processing device 20 stops communication during communication. In this case, in steps S702 and S703, the USB state management unit 122 of the communication device 10 transitions the USB device 100 to the SUSPEND state 607 when it detects that the BUS has been inactive for 3 ms or more. Note that in USB 2.0, the SUSPEND state 607 is released when the BUS becomes active.

[0047] In USB 3.0, the USB device 100 transitions to the SUSPEND state 607 when the USB host requests the USB device 100 to transition to the SUSPEND state 607 .

[0048] 8 is a diagram (USB 3.0) for explaining an example of a process for transitioning to a suspended state. For example, in step S801, the information processing device 20 issues a SUSPEND state transition request.

[0049] In this case, in step S802, the USB state management unit 122 of the communication device 10 returns OK to the SUSPEND state transition request. Also, in steps S803 and S804, the USB state management unit 122 returns SUSPEND state transition acknowledgement to the information processing device 20 and executes transition to the SUSPEND state.

[0050] When the information processing device 20 receives the SUSPEND state transition acknowledgement in step S805, the information processing device 20 executes transition to the SUSPEND state in step S806.

[0051] <Processing flow> Next, the processing flow of the state control method according to the first embodiment will be described.

[0052] (State control processing) 9 is a flowchart showing an example of a state control process according to the first embodiment. This process shows an example of a state control process executed by the communication device 10 having the functional configuration shown in FIG.

[0053] In step S901, the system control unit 205 determines whether the power state of the communication device 10 managed by the power state management unit 204 is the power saving state 502. If the communication device 10 is in the power saving state 502, the system control unit 205 shifts the process to step S902. On the other hand, if the communication device 10 is not in the power saving state, the system control unit 205 executes the process of step S901 again.

[0054] In step S902, the system control unit 205 determines whether a cable is connected to the USB I / F 110, based on the USB information managed by the communication event management unit 203. As described above, the communication event management unit 203 manages USB information notified by the USB event management unit 123, including the operating state of the USB device 100 and the connection state of the USB cable, etc.

[0055] If a cable is connected to the USB I / F 110, the system control unit 205 causes the process to proceed to step S903. On the other hand, if a cable is not connected to the USB I / F 110, the system control unit 205 causes the process to proceed to step S906.

[0056] In step S903, the system control unit 205 determines whether the operating state of the USB device 100 is suspended (SUSPEND state 607) based on the USB information managed by the communication event management unit 203. In other words, it determines whether the USB device 100 is in an operating state in which communication with other devices is paused. If the USB device 100 is suspended, the system control unit 205 causes the process to proceed to step S906. On the other hand, if the USB device 100 is not suspended, the system control unit 205 causes the process to proceed to step S904.

[0057] In steps S904 and S905, the system control unit 205 waits for a state transition of the USB device 100, and if the state of the USB device 100 has transitioned, the process returns to step S903. As described above, the USB event management unit 123 receives USB information from the endpoint control unit 121 and the USB state management unit 122 and notifies the communication event management unit 203. Therefore, the system control unit 205 can determine whether the state of the USB device 100 has transitioned by, for example, acquiring the USB information managed by the communication event management unit 203 at predetermined time intervals.

[0058] In step S906, the system control unit 205 starts a timer using the timer control unit 206. That is, it starts measuring the time that the USB device 100 remains in the suspended state (SUSPEND state 607).

[0059] Due to the revision of Lot 6 (power saving standard) of the European law regulation ErP (Energy-related Products) Directive, it is now necessary to turn off the main power supply if the network is disconnected for a predetermined period of time. The system control unit 205 starts measuring the time using the timer described above to measure this predetermined period of time. The predetermined period of time is, for example, 20 minutes, but can be set according to the time required by law or regulation.

[0060] In step S907, the system control unit 205 determines whether a communication event has been detected during timer activation, based on information about communication events managed by the communication event management unit 203. As described above, the communication event management unit 203 manages information about communication events notified from the USB event management unit 123, the wired LAN event management unit 201, the wireless LAN event management unit 202, etc.

[0061] If a communication event is detected while the timer is running, the system control unit 205 shifts the process to step S908. On the other hand, if a communication event is not detected while the timer is running, the system control unit 205 shifts the process to step S909.

[0062] In step S908, the system control unit 205 clears (initializes) the timer that is currently measuring using the timer control unit 206, and returns the process to step S901. On the other hand, in step S909, the system control unit 205 uses the timer control unit 206 to end the timer that is currently measuring.

[0063] In step S910, the system control unit 205 controls to turn off the main power of the communication device 10. For example, the system control unit 205 instructs the main power management unit 207 to turn off the main power. That is, when a timer measures that the suspended state (SUSPEND state 607) of the USB device 100 has continued for a predetermined time, the communication device 10 transitions from the current power saving state to a power state in which the main power is off, which consumes less power.

[0064] By the process of FIG. 9, in the communication device 10 that communicates with another device (information processing device 20) via a USB interface, it is possible to reduce the power consumption of the communication device 10 when communication is not being performed.

[0065] [Second embodiment] (State transition of communication device) 10 is a diagram showing an example of state transitions of a communication device according to the second embodiment. The communication device 10 according to the second embodiment has an automatic transition off state 1001 in addition to a normal state 501, a power saving state 502, and a main power off state 503.

[0066] The normal state 501 is a power state in which the communication device 10 is normally activated and is capable of executing predetermined functions of the communication device 10. In the normal state 501, the communication device 10 transitions to a power saving state 502 by power saving state transition control, and transitions to a main power off state 503 by pressing the main power button.

[0067] The power saving state (first power saving state) 502 is a power state in which some of the hardware included in the communication device 10 is stopped and consumes less power than the normal state 501. The power saving state 502 is an example of the first power saving state in which power consumption is less than that of the normal state 501 in which normal operation is possible.

[0068] In the power saving state 502, the communication device 10 transitions to the normal state 501 by recovery control from the power saving state 502. Furthermore, when the main power button is pressed, the communication device 10 transitions to the main power off state 503. Furthermore, when the USB device 100 is in a suspended state and the wired LAN port and the wireless LAN port are disabled, the communication device 10 transitions to the automatic transition off state 1001.

[0069] The main power off state 503 is a power state in which the power of the communication device 10 is completely turned off. In the main power off state 503, the communication device 10 transitions to the normal state 501 when the main power button is pressed.

[0070] The automatic transition off state (second power saving state) 1001 is an off state to which the device automatically transitions without pressing the main power button or the like. The automatic transition off state 1001 consumes less power than the power saving state 502, and is a state in which most of the communication device 10 is stopped and only minimal functions are operating. The automatic transition off state 1001 is an example of a second power saving state that consumes less power than the first power saving state and is capable of detecting the connection status of a cable connected to the communication device 10.

[0071] In the automatic transition off state 1001, when the communication device 10 detects the insertion of a communication cable such as a wireless LAN cable or a USB cable, the communication device 10 transitions to the power saving state 502. Furthermore, when the main power button is pressed, the communication device 10 transitions to the normal state 501.

[0072] (USB device state transition) 11 is a diagram showing an example of state transitions of a USB device according to the second embodiment. The operating states of the USB device 100 according to the second embodiment include a PAUSE state 1101 in addition to a CABLE UNCONNECTED state 601, an ATTACHED state 602, a POWERED state 603, a DEFAULT state 604, an ADDRESS state 605, a CONFIGURED state 606, and a SUSPEND state 607.

[0073] The cable disconnected state 601, the attached state 602, the powered state 603, the default state 604, the address state 605, the configured state 606, and the suspended state 607 are the same as the operating states described in FIG.

[0074] However, if the communication apparatus 10 transitions from the SUSPEND state 607 to the automatic transition OFF state 1001 described with reference to FIG.

[0075] In the PAUSE state 1101, all functions except for the cable removal detection function are turned off and communication via the BUS is suspended, so from the perspective of the USB host (information processing device 20), the state is disconnected. The PAUSE state 1101 consumes less power than the SUSPEND state 607. In the PAUSE state 1101, if the USB device 100 detects cable removal, it transitions to the cable unconnected state 601.

[0076] The reason for providing the PAUSE state 1101 is that if the communication apparatus 10 transitions to the automatic transition OFF state 1001 while the state transition of the USB device 100 remains the same as in the first embodiment, the operating state of the USB device 100 becomes the cable unconnected state 601. However, at this time, a cable is actually connected, and an inconsistency occurs in the operating state of the USB device 100. Therefore, in the second embodiment, the inconsistency in the operating state of the USB device 100 is resolved by newly defining the PAUSE state 1101, which is a state in which the USB cable is connected but no communication is occurring.

[0077] <Processing flow> Next, the processing flow of the state control method according to the second embodiment will be described.

[0078] (State control processing) 12 and 13 are flowcharts showing an example of state control processing according to the second embodiment. This processing shows another example of state control processing executed by the communication device 10 having the functional configuration shown in Fig. 2. Note that detailed description of processing content similar to the state control processing according to the first embodiment described in Fig. 9 will be omitted here.

[0079] In step S1201, system control unit 205 determines whether the power state of communication device 10 managed by power state management unit 204 is in power saving state (first power saving state) 502. If communication device 10 is in power saving state 502, system control unit 205 transitions the process to step S1202. On the other hand, if communication device 10 is not in the power saving state, system control unit 205 executes the process of step S1201 again.

[0080] In step S1202, the system control unit 205 determines whether the wired LAN port and the wireless LAN port are disabled based on the connection status of the communication ports managed by the communication event management unit 203. As described above, the communication event management unit 203 manages the connection status of the communication ports notified by the wired LAN event management unit 201 and the wireless LAN event management unit 202. If the wired LAN port and the wireless LAN port are disabled, the system control unit 205 transitions the process to step S1203. On the other hand, if the wired LAN port and the wireless LAN port are not disabled, the system control unit 205 returns the process to step S1201.

[0081] In step S1203, the system control unit 205 determines whether or not a cable is connected to the USB I / F 110, based on the USB information managed by the communication event management unit 203. If a cable is connected to the USB I / F 110, the system control unit 205 causes the process to proceed to step S1204. On the other hand, if a cable is not connected to the USB I / F 110, the system control unit 205 causes the process to proceed to step S1207.

[0082] In step S1204, the system control unit 205 determines whether the operating state of the USB device 100 is suspended (SUSPEND state 607) based on the USB information managed by the communication event management unit 203. In other words, it determines whether the USB device 100 is in an operating state in which communication with other devices is paused. If the USB device 100 is in a suspended state, the system control unit 205 causes the process to proceed to step S1207. On the other hand, if the USB device 100 is not in a suspended state, the system control unit 205 causes the process to proceed to step S1205.

[0083] In steps S1205 and S1206, the system control unit 205 waits for the state of the USB device 100 to change, and when the state of the USB device 100 has changed, the process returns to step S1204.

[0084] In step S1207, the system control unit 205 starts a timer using the timer control unit 206. That is, it starts measuring the time that the USB device 100 remains in the suspended state (SUSPEND state 607).

[0085] In step S1208, system control unit 205 determines whether a communication event has been detected while the timer is running, based on information about communication events managed by communication event management unit 203. If a communication event has been detected while the timer is running, system control unit 205 transitions the process to step S1209. On the other hand, if a communication event has not been detected while the timer is running, system control unit 205 transitions the process to step S1210.

[0086] In step S1209, system control unit 205 clears (initializes) the timer that is currently measuring using timer control unit 206, and returns the process to step S1201. On the other hand, in step S1210, system control unit 205 ends the timer that is currently measuring using timer control unit 206, and executes the process of FIG.

[0087] 13, the system control unit 205 transitions the power state of the communication device 10 to the automatic transition off state 1001. That is, when the timer measures that the suspended state (SUSPEND state 607) of the USB device 100 has continued for a predetermined time, the communication device 10 transitions from the current power saving state to the automatic transition off state, which consumes less power. For example, the system control unit 205 notifies the power state management unit 204, the communication event management unit 203, etc. of the transition to the automatic transition off state 1001, and then instructs the power saving management unit 208 to transition to the automatic transition off state 1001.

[0088] In step S1302, the USB device 100 transitions to the paused state (PAUSE state 1101). For example, upon receiving a notification of the automatic transition OFF state 1001 from the communication event manager 203, the USB event manager 123 transitions the operating state of the USB device 100 to the paused state.

[0089] In step S1303, system control unit 205 determines whether the main power button of communication device 10 has been pressed. If the main power button has not been pressed, system control unit 205 advances the process to step S1304. On the other hand, if the main power button has been pressed, system control unit 205 returns the process to step S1201 in FIG. 12.

[0090] In step S1304, the system control unit 205 determines whether a communication cable (USB cable or LAN cable) has been detected, based on information about communication events managed by the communication event management unit 203. As described above, the communication event management unit 203 manages the connection status of the USB cable, etc., notified by the USB event management unit 123, and the connection status of the communication port, etc., notified by the wired LAN event management unit 201.

[0091] If a communication cable is detected, the system control unit 205 returns the process to step S1201 in Fig. 12. On the other hand, if a communication cable is not detected, the system control unit 205 ends the processes in Figs. 12 and 13 (maintains the automatic transition off state 1001).

[0092] 12 and 13, the communication device 10 can automatically transition from the automatic transition off state 1001, which is a low power consumption state similar to the main power off state 503, to the power saving state 502 upon detection of a communication cable, without having to press the main power button.

[0093] <Modification> In the above first embodiment, a flow is described in which the state control process is executed when the communication device is in a power saving state (YES in step S901) and when a cable is connected to the USB I / F (YES in step S902), but the state control process may be executed when the communication device is in either of these states, or when the communication device is in neither of these states.

[0094] Furthermore, in the above first embodiment, the main power off state is described as a power state that consumes less power than the current power state (power saving state), but it is also possible to transition to a power state that consumes more power than the main power off state but less power than the power saving state.

[0095] <Supplementary information> Each function of each embodiment described above can be realized by one or more processing circuits. Here, the term "processing circuit" in this specification includes a processor programmed to perform each function by software, such as a processor implemented by an electronic circuit, as well as devices such as an ASIC (Application Specific Integrated Circuit), a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), and conventional circuit modules designed to perform each of the functions described above.

[0096] <Summary of the embodiment> This specification discloses the following communication device, state control method, and program. (Appendix 1) A communication device comprising a USB device having a USB interface and capable of communicating with other devices via the USB interface, a USB status management unit that manages the operating status of the USB device; a power state management unit that manages a power state of the communication device; a system control unit that executes a state control process to control the transition of the communication device to a power state that consumes less power than a current power state when the operation state in which the USB device is suspending communication with the other device continues for a predetermined time; A communication device comprising: (Appendix 2) The communication device according to claim 1, wherein the system control unit executes the state control process when the current power state is a power saving state that consumes less power than a normal state in which normal operation is possible. (Appendix 3) 3. The communication device according to claim 1, wherein the system control unit executes the state control process when a cable is connected to the USB interface. (Appendix 4) The communication device according to any one of Supplementary Note 1 to Supplementary Note 3, wherein the power state in which power consumption is lower than that of the current power state includes a power-off state. (Appendix 5) the communication device includes a communication interface different from the USB interface, 4. The communication device according to claim 1, wherein the system control unit executes the state control process when the communication interface is disabled. (Appendix 6) A communication device as described in Appendix 5, wherein a power state that consumes less power than the current power state includes a power state in which a function to return to the power saving state is enabled when a cable is connected to the USB interface or the communication interface. (Appendix 7) The communication device according to claim 5 or 6, wherein the power state in which power consumption is lower than the current power state includes a power state in which a function for detecting removal of a cable connected to the USB interface is enabled. (Appendix 8) the power supply state of the communication device includes a first power saving state in which power consumption is lower than a normal state in which normal operation is possible, and a second power saving state in which power consumption is lower than the first power saving state and in which a connection state of a cable connected to the communication device can be detected; the system control unit transitions the communication device to the second power saving state when an operating state in which the USB device is suspending communication with other devices continues for a predetermined period in the first power saving state; 2. The communication device of claim 1. (Appendix 9) a communication device comprising a USB device having a USB interface and capable of communicating with other devices via the USB interface, a process for managing the operating state of the USB device; a process for managing a power state of the communication device; a state control process for controlling the transition of the communication device to a power state with less power consumption than the current power state when the operating state in which the USB device is suspending communication with the other device continues for a predetermined time; Executes a state control method. (Appendix 10) a communication device that includes a USB device having a USB interface and that can communicate with other devices via the USB interface; a process for managing the operating state of the USB device; a process for managing a power state of the communication device; a state control process for controlling the transition of the communication device to a power state with less power consumption than the current power state when the operating state in which the USB device is suspending communication with the other device continues for a predetermined time; A program that executes.

[0097] Although the embodiments of the present invention have been described above, the present invention is not limited to such specific embodiments, and various modifications and applications are possible within the scope of the gist of the present invention described in the claims. [Explanation of symbols]

[0098] 1. Communication Systems 10. Communications equipment 11 Wired LAN I / F (communication interface) 12 Wireless LAN module (communication interface) 20 Information processing equipment (other equipment) 100 USB devices 110 USB I / F (USB interface) 122 USB status management unit 204 Power Status Management Unit 501 Normal state 502 Power saving state (first power saving state) 503 Main power off state (power off state) 1001 Automatic transition to OFF state (second power saving state) 1101 PAUSE state [Prior art documents] [Patent documents]

[0099] [Patent Document 1] Japanese Patent Application Publication No. 2017-091595

Claims

1. A communication apparatus including a USB device having a USB interface and capable of communicating with another apparatus via the USB interface, a USB status management unit that manages the operating status of the USB device; a power state management unit that manages a power state of the communication device; a system control unit that executes a state control process to control the transition of the communication device to a power state with less power consumption than a current power state when the operation state in which the USB device is suspending communication with the other device continues for a predetermined time; A communication device comprising:

2. The communication device according to claim 1 , wherein the system control unit executes the state control process when the current power supply state is a power saving state in which power consumption is less than a normal state in which normal operation is possible.

3. The communication device according to claim 2 , wherein the system control unit executes the state control process when a cable is connected to the USB interface.

4. The communication device according to claim 1 , wherein the power state that consumes less power than the current power state includes a power-off state.

5. the communication device includes a communication interface different from the USB interface; The communication device according to claim 1 , wherein the system control unit executes the state control process when the communication interface is disabled.

6. The communication device according to claim 5 , wherein the power state consuming less power than the current power state includes a power state in which a function of returning to the current power state is enabled when a cable is connected to the USB interface or the communication interface.

7. The communication device according to claim 5 , wherein the power state in which power consumption is less than that of the current power state includes a power state in which a function for detecting removal of a cable connected to the USB interface is enabled.

8. the power supply state of the communication device includes a first power saving state in which power consumption is less than a normal state in which normal operation is possible, and a second power saving state in which power consumption is less than the first power saving state and in which a connection state of a cable connected to the communication device can be detected; the system control unit transitions the communication device to the second power saving state when an operating state in which the USB device is suspending communication with other devices continues for a predetermined period in the first power saving state; The communication device according to claim 1 .

9. A communication apparatus includes a USB device having a USB interface, and is capable of communicating with another apparatus via the USB interface, A process for managing the operating state of the USB device; a process for managing a power state of the communication device; a state control process for controlling the transition of the communication device to a power state with less power consumption than a current power state when the operation state in which the USB device is suspending communication with the other device continues for a predetermined time; Executes a state control method.

10. A communication device includes a USB device having a USB interface and capable of communicating with other devices via the USB interface, A process for managing the operating state of the USB device; a process for managing a power state of the communication device; a state control process for controlling the transition of the communication device to a power state with less power consumption than a current power state when the operation state in which the USB device is suspending communication with the other device continues for a predetermined time; A program that executes.

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