JP5072923B2 - Electronics - Google Patents

Description

  The present invention relates to an electronic device having a wireless communication function, a computer system, and a communication control method.

  In recent years, various portable personal computers of a laptop type or a notebook type have been developed. In addition, as an external device for extending the functions of a portable personal computer, an expansion unit called a so-called docking station has been developed.

  Patent Document 1 discloses a system including an expansion unit and a computer. In this system, the expansion unit includes a wired LAN controller, and the computer includes a wireless communication unit. In the undocking state, the computer is wirelessly connected to the access point by the wireless communication unit. In the docking state, the computer is connected to the network via a wired LAN controller in the expansion unit.

  Patent document 2 discloses a camera system including a digital camera and an expansion unit. In this camera system, power is supplied from the extension unit to the digital camera via a cable, and data communication between the extension unit and the digital camera is executed via this cable.

JP 2002-108521 A JP 2003-309749 A

  However, both the system of Patent Document 1 and the system of Patent Document 2 use a wired connection for connection between an electronic device such as a computer and a camera and its extension unit. Such a wired connection impairs the portability of an electronic device such as a computer or a camera, or restricts the place where the electronic device is used.

  If the wireless connection between the electronic device and the expansion unit is realized, the function expansion of the electronic device can be realized without impairing the portability of the electronic device. However, in general, in the short-range wireless communication method for wirelessly connecting devices, the number of usable frequency channels is limited. For this reason, in some specific places of use such as offices, if some devices are already performing wireless communication using the short-range wireless communication method, there will be no unused frequency channels and new wireless communication will no longer occur. Will not be able to start. Even if an unused frequency channel exists, wireless communication may not be performed normally depending on the surrounding radio wave environment.

  Therefore, even if a wireless communication unit for short-range wireless communication is installed in each of the electronic device and the extension unit, wireless communication between the electronic device and the extension unit cannot always be executed.

  Therefore, it is necessary to realize a new function capable of executing communication between an electronic device and an external device such as an expansion unit even in a situation where wireless communication cannot be performed.

  The present invention has been made in consideration of the above-described circumstances, and provides an electronic device capable of executing communication between the electronic device and an external device such as an expansion unit even in a situation where wireless communication cannot be performed. The purpose is to do.

In order to solve the above-described problems, an electronic device according to the present invention includes a communication unit that performs communication with an external device in a wireless communication mode or a wired communication mode, and power supplied from the external device via a power cable. A power supply circuit that generates operating power to be supplied to each component in the electronic device, and a high-frequency circuit of the communication unit, and a signal input / output port of the high-frequency circuit is connected to one of the wireless communication antenna and the power cable. A switch unit to be coupled, and the wireless communication mode for controlling the switch unit to communicate with the external device, and to transmit / receive a wireless signal between the high-frequency circuit and the external device via the wireless communication antenna; , and a control means for switching between said wired communication mode to transmit and receive the radio signal between the high frequency circuit and the external device via the power cable The wireless communication mode is executed using a frequency channel selected from a plurality of frequency channels, and the control unit is configured to switch the switch unit when there is no unused frequency channel among the plurality of frequency channels. To control the communication mode with the external device to the wired communication mode.

  According to the present invention, communication between an electronic device and an external device such as an expansion unit can be performed even in a situation where wireless communication cannot be performed.

1 is a block diagram illustrating a configuration of an electronic device according to an embodiment of the present invention. The block diagram which shows the example of a structure of each of the electronic device corresponding to the case where communication with the electronic device of the embodiment and an external device is performed via a power cable, and an external device. 2 is an exemplary block diagram showing an example of the system configuration of the electronic apparatus of the embodiment. FIG. 2 is an exemplary block diagram showing an example of the system configuration of an external device that performs communication with the electronic device of the embodiment. FIG. 6 is an exemplary flowchart illustrating the procedure of a communication control process which is executed by the electronic apparatus of the embodiment. 6 is an exemplary flowchart illustrating a procedure of user setting processing which is executed by the electronic apparatus of the embodiment. The block diagram which shows another example of a structure of each of the electronic device corresponding to the case where communication with the electronic device of the embodiment and an external device is performed via a power cable, and an external device. FIG. 8 is a diagram illustrating a configuration example of a substrate built-in antenna used in the configuration of the electronic apparatus illustrated in FIG. 7. FIG. 8 is a diagram illustrating another configuration example of a substrate built-in antenna used in the configuration of the electronic apparatus illustrated in FIG. 7. The block diagram which shows another example of the structure of the electronic device corresponding to the case where communication with the electronic device of the embodiment and an external device is performed via a power cable, and each external device. FIG. 6 is an exemplary block diagram illustrating still another example of the configuration of each of the electronic device and the external device corresponding to a case where communication between the electronic device and the external device according to the embodiment is performed via a power cable. The block diagram which shows the further another example of a structure of each of the electronic device corresponding to the case where communication with the electronic device of the embodiment and an external device is performed via a power cable, and an external device. The block diagram which shows the example of a structure of each of the electronic device corresponding to the case where communication with the electronic device of the embodiment and an external device is performed via a cable different from a power cable, and an external device. 4 is an exemplary block diagram illustrating another example of the configuration of each of the electronic device and the external device corresponding to a case where communication between the electronic device and the external device according to the embodiment is performed via a cable different from the power cable. FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  First, with reference to FIG. 1, the structure of the electronic device which concerns on one Embodiment of this invention is demonstrated. The electronic apparatus is realized as a computer 10, for example. The computer 10 is a portable information processing apparatus such as a portable personal computer. The computer 10 includes a main body 11 and a display unit 12 attached to the main body 11. The display unit 12 includes a liquid crystal display (LCD) 121. On the upper surface of the main body 11, a keyboard 13, a power button 14, a touch pad 16, and the like are arranged.

  The computer 10 has a function of executing wireless communication with the external device 20. The external device 20 is realized, for example, as a wireless docking station that is an expansion unit for expanding the functions of the computer 10. The computer 10 can use various peripheral devices connected to the external device 20 by wireless connection to the external device 20. In addition, the computer 10 transmits a digital video signal such as a digital visual interface (DVI) signal to the external device 20 by a wireless signal, so that a screen image is displayed on a display device (DVI monitor device) connected to the external device 20. Can be displayed. The wireless communication between the computer 10 and the external device 20 is performed using, for example, UWB (Ultra Wideband), which is a short-range wireless communication method that is faster than a wireless LAN.

  In the UWB standard, 14 frequency channels that are split in a frequency band from about 3.1 GHz to about 10.6 GHz are defined. However, the usable frequency range is limited depending on the country or region. For example, in Japan, the frequency band that can be used for UWB communication is, for example, from 3.4 GHz to 4.8 GHz, and three frequency channels allocated within the frequency band from 3.4 GHz to 4.8 GHz can be used. It is. Therefore, if three frequency channels have already been used in a certain place such as an office, there is no unused frequency channel, and therefore it is not possible to start a new UWB communication in that place.

  In order to enable the computer 10 of the present embodiment to execute communication with the external device 20 even in a situation where unused frequency channels are insufficient or in a situation where radio wave interference occurs, A hybrid wireless communication function for switching the communication mode with the external device 20 between the wireless communication mode and the wired communication mode is provided. That is, in the communication between the computer 10 and the external device 20, normally, a wireless connection is used. However, when the wireless connection cannot be used, or when the user desires a wired connection, the computer 10 and the external device 20 are externally connected. Communication with the device 20 can be performed using a wired connection. In the present embodiment, the same wireless signal (RF signal) is used in both the wireless communication mode and the wired communication mode. That is, in the wired communication mode, a wireless signal used in the wireless communication mode is transmitted via the cable 1 that connects the computer 10 and the external device 20.

  In order to realize the above-described hybrid wireless communication function, the computer 10 includes a wireless communication unit 31, an RF switch unit 32, a wireless communication antenna 33, a wired transmission line 34, and a control unit 35.

  The wireless communication unit 31 performs wireless communication according to a short-range wireless communication method such as the UWB standard. The wireless communication unit 31 performs wireless communication with the external device 20 using a frequency channel selected from a plurality of frequency channels (for example, three frequency channels). The selection of the frequency channel to be used can be specified in advance by the user, for example. Further, an unused frequency channel may be selected from the three frequency channels, and the frequency channel may be selected as a frequency channel to be used.

  The wireless communication unit 31 includes a high-frequency circuit (RF circuit) for transmitting and receiving a wireless signal (RF signal). Normally, the radio signal input / output port of the high frequency circuit is directly connected to the radio communication antenna 33 provided in the computer 10, but in this embodiment, the radio signal input / output port of the high frequency circuit has an RF switch section. 32 is connected.

  The RF switch unit 32 is a switch unit that couples the radio signal input / output port of the high-frequency circuit in the radio communication unit 31 to one of the radio communication antenna 33 and the cable 1 connected to the external device 20. In the wireless communication mode, the wireless signal input / output port of the high frequency circuit is connected to the wireless communication antenna 33 by the RF switch unit 32. On the other hand, in the wired communication mode, the radio signal input / output port of the high-frequency circuit is connected to the wired port by the RF switch unit 32. Specifically, the computer 10 is provided with a connector 15 to which the cable 1 is connected and a wired transmission line 34 connected to the connector 15. In the wired communication mode, the wireless signal input of the high-frequency circuit is provided. The output port is connected to the cable 1 via the RF switch unit 32, the wired transmission line 34, and the connector 15.

  The control unit 35 controls the RF switch unit 32 to change the communication mode with the external device to a wireless communication mode in which a wireless signal is transmitted and received between the external device 20 and the wireless communication unit 31 via the wireless communication antenna 33. Switching between a wired communication mode in which wireless signals are transmitted and received between the external device 20 and the wireless communication unit 31 via the cable 1 is performed.

  When there is no unused frequency channel among the plurality of frequency channels, or when the occurrence of radio wave interference is detected during a period in which communication with the external device 20 is being performed in the wireless communication mode, the control unit 35 A message prompting the user to connect the cable 1 to the computer 10, that is, to connect the computer 10 and the external device 20 via the cable 1, is displayed on the display screen of the LCD 121. After the cable 1 is connected to the computer 10, the control unit 35 controls the RF switch unit 31 to switch the connection destination of the RF switch unit 31 from the wireless communication antenna 33 to the wired port. Set the communication mode to wired communication mode.

  If the cable 1 is already connected to the computer 10, the communication mode may be immediately switched to the wired communication mode. In addition, when the communication is started, it is determined whether or not the cable 1 is connected to the computer 10. When the cable 1 is connected to the computer 10, the wired communication mode is preferentially used over the wireless communication mode. You may make it do. Further, even when the cable 1 is connected to the computer 10, the wireless communication mode can be used. In this case, the user can select whether to use the wired communication mode or the wireless communication mode.

  In the present embodiment, wired communication is performed using the same wireless signal (modulated wave) as the wireless signal (modulated wave) used for wireless communication. As a result, the wireless communication unit 31 can be shared for wireless communication and wired communication, and there is no need to provide a new circuit dedicated to wired communication, so that the cost can be reduced. Transmission loss of the radio signal by the cable 1 is about 10 db to 20 db. On the other hand, the transmission loss of radio signals in the air is about 10 db to 40 db. Thus, since the transmission loss of the wireless signal by the cable 1 is within the range of the transmission loss of the wireless signal in the air, the wireless communication unit 31 performs the same modulation / demodulation operation in both the wired communication mode and the wireless communication mode. Communication with the external device 20 can be normally performed only by performing the above.

  For example, a coaxial cable can be used as the cable 1. Further, as the cable 1, a power cable for supplying power output from the external device 20 to the computer 10 may be used. By using a power cable, it is not necessary to provide a connector for connecting a cable dedicated to communication, and the cost can be further reduced.

  The external device 20 also has the same hybrid wireless communication function as the computer 10. That is, the external device 20 includes a wireless communication unit 41, an RF switch unit 42, a wireless communication antenna 43, a wired transmission line 44, and a control unit 35.

  The wireless communication unit 41 performs wireless communication according to a short-range wireless communication method such as the UWB standard, which is the same as the wireless communication unit 31 of the computer 10. The wireless communication unit 41 performs wireless communication with the computer 10 using a frequency channel selected from a plurality of frequency channels (for example, three frequency channels). The selection of the frequency channel to be used can be specified in advance by the user, for example. The wireless communication unit 41 can also select / change a frequency channel to be used in accordance with an instruction from the computer 10.

  The wireless communication unit 41 includes a high-frequency circuit (RF circuit) for transmitting and receiving a wireless signal (RF signal). Normally, the radio signal input / output port of the high frequency circuit is directly connected to the radio communication antenna 43 provided in the external device 20, but in this embodiment, the radio signal input / output port of the high frequency circuit has an RF switch. The part 42 is connected.

  The RF switch unit 42 is a switch unit that couples the radio signal input / output port of the high-frequency circuit in the radio communication unit 41 to one of the radio communication antenna 43 and the cable 1 led out from the external device 20. In the wireless communication mode, the wireless signal input / output port of the high frequency circuit is connected to the wireless communication antenna 43 by the RF switch unit 42. On the other hand, in the wired communication mode, the radio signal input / output port of the high-frequency circuit is connected to the wired port by the RF switch unit 42. Specifically, the external device 20 is provided with a connector 21 to which the cable 1 is connected and a wired transmission line 44 connected to the connector 21. In the wired communication mode, the radio signal of the high-frequency circuit is provided. The input / output port is connected to the cable 1 via the RF switch unit 42, the wired transmission line 44, and the connector 21.

  The control unit 45 controls the RF switch unit 42 to change the communication mode with the computer 10, the wireless communication mode for transmitting and receiving wireless signals between the computer 10 and the wireless communication unit 41 via the wireless communication antenna 43, and The mode is switched between a wired communication mode in which wireless signals are transmitted and received between the computer 10 and the wireless communication unit 41 via the cable 1.

  The control unit 45 monitors, for example, the packet error rate in the currently used communication mode, and controls the RF switch unit 42 when the packet error rate exceeds a reference value to set another communication mode to be used. Switch to communication mode. Thereby, the communication mode used in the external device 20 can be switched so as to follow the switching of the communication mode used in the computer 10.

  FIG. 2 shows examples of configurations of the computer 10 and the external device 20 corresponding to the case where a power cable is used as the cable 1.

  The computer 10 includes a capacitor 51 and a filter (Band Rejection Filter; BRF) 52. The RF switch unit 32 is coupled to a power supply line in the power cable 1 via a capacitor 51. Specifically, the RF switch unit 32 is connected to a power line in the computer 10 that is coupled to a power line in the power cable 1 via the connector 15. The capacitor 51 passes a signal component corresponding to a frequency band (for example, 3.1 GHz to 5.2 GHz) of a wireless signal transmitted and received by the wireless communication unit 31. The capacitor 51 has a function of superimposing a radio signal transmitted from the radio communication unit 31 on a power line in the power cable 1 and a function of extracting a radio signal from the power line in the power cable 1. The capacitor 51 can improve the frequency characteristics of a radio signal transmitted / received via the power cable 1.

  A filter (Band Rejection Filter; BRF) 52 is a filter circuit for preventing a radio signal transmitted via the power cable 1 from entering the power circuit 53 in the computer 10. The filter (Band Rejection Filter; BRF) 52 prevents a signal component corresponding to a frequency band (for example, 3.1 GHz to 5.2 GHz) of a radio signal transmitted and received by the radio communication unit 31 from passing. This filter (Band Rejection Filter; BRF) 52 may be composed of a pattern filter or a choke coil. This filter (Band Rejection Filter; BRF) 52 functions as a splitter in cooperation with the capacitor 51.

  The power supply circuit 53 generates operating power to be supplied to each component in the computer 10 from the power supplied from the external device 20 via the power cable 1.

  The wireless communication unit 31 is realized as one independent wireless module, and the wireless module includes the RF unit 311 and the above-described RF switch unit 32. The RF unit 311 is the above-described high-frequency circuit, and includes, for example, hardware (PHY) corresponding to the physical layer of UWB and hardware (MAC) corresponding to the MAC layer. The radio signal input / output port of the RF unit 311 is connected to the RF switch unit 32 via a signal wiring in the radio communication unit 31.

  The external device 20 includes a capacitor 61 and a filter (BRF) 62. The RF switch unit 42 is coupled to the power line in the power cable 1 via the capacitor 61. Specifically, the RF switch unit 42 is connected to a power supply line in the external device 20.

  The capacitor 61 passes a signal component corresponding to a frequency band (for example, 3.1 GHz to 5.2 GHz) of a wireless signal transmitted and received by the wireless communication unit 41. The capacitor 61 has a function of superimposing a radio signal transmitted from the radio communication unit 41 on a power line in the power cable 1 and a function of extracting a radio signal from the power line in the power cable 1. The capacitor 61 can improve the frequency characteristics of the radio signal transmitted and received via the power cable 1.

  The filter (BRF) 62 is a filter circuit for preventing a radio signal transmitted through the power cable 1 from entering the power circuit 63 in the external device 20. The filter (BRF) 62 prevents a signal component corresponding to a frequency band (for example, 3.1 GHz to 5.2 GHz) of a wireless signal transmitted and received by the wireless communication unit 41 from passing. This filter (Band Rejection Filter; BRF) 62 may be composed of a pattern filter or a choke coil. This filter (Band Rejection Filter; BRF) 62 functions as a splitter in cooperation with the capacitor 61.

  The power supply circuit 63 generates power (DC power supply) to be supplied to the computer 10 and operating power (DC power supply) to be supplied to each component in the external device 20 from an external power supply (AC power supply).

  The radio communication unit 41 is realized as one independent radio module, and the radio module includes the RF unit 411 and the above-described RF switch unit 42. The RF unit 411 is the above-described high-frequency circuit, and includes, for example, hardware (PHY) corresponding to the physical layer of UWB and hardware (MAC) corresponding to the MAC layer. The radio signal input / output port of the RF unit 411 is connected to the RF switch unit 42 via a signal wiring in the radio communication unit 41.

  Next, a system configuration example of the computer 10 will be described with reference to FIG. The system configuration of FIG. 3 corresponds to the case where a power cable is used as the cable 1.

  The computer 10 includes a CPU 211, a north bridge 212, a main memory 213, a display controller 214, a south bridge 215, a BIOS-ROM 216, in addition to the above-described wireless communication unit 31, RF switch unit 32, capacitor 51, filter 52, and power supply circuit 53. A hard disk drive (HDD) 217 as a nonvolatile storage device, an embedded controller / keyboard controller IC (EC / KBC) 218, a video signal output unit 219, and the like are provided.

  The CPU 211 is a processor that controls the operation of the computer 10 and executes an operating system (OS) and various application / utility programs loaded from the hard disk drive (HDD) 217 to the main memory 213. The application / utility program includes a communication control program. This communication control program is a program for controlling the wireless communication unit 31. By executing this communication control program, the CPU 211 functions as the control unit 35 described above.

  The CPU 111 also executes a basic input output system (BIOS) stored in the BIOS-ROM 216. The BIOS is a program for hardware control.

  The north bridge 212 is a bridge device that connects the local bus of the CPU 211 and the south bridge 215. The north bridge 212 also has a function of executing communication with the display controller 214.

  The display controller 214 is a graphics controller that controls an LCD (Liquid Crystal Display) 121 used as a display monitor of the computer 10. The display controller 214 generates a video signal that forms a screen image to be displayed on the display screen of the LCD 124. The video signal generated by the display controller 214 is sent to the LCD 124. The display controller 214 can also send a video signal sent to the LCD 124 to the video signal output unit 219.

  The video signal output unit 219 converts the video signal from the display controller 214 into a digital video signal of a predetermined format such as the DVI format, and outputs the digital video signal. This digital video signal is sent to the wireless communication unit 31. Note that a function for controlling a digital video signal such as a DVI signal may be provided in the display controller 214. In this case, the display controller 214 functions as a video signal output unit that outputs a digital video signal.

  The south bridge 215 is a bridge device that controls various I / O devices. The south bridge 215 includes a USB controller 301 and the like.

  The wireless communication unit 31 is connected to the south bridge 215, and converts the USB signal from the USB controller 301 into a signal (UWB signal) in a predetermined format such as the UWB format under the control of the communication control program. A wireless signal corresponding to the received signal (that is, a wireless signal modulated by a USB signal) can be transmitted to the external device 20. In the wireless communication mode, the wireless signal modulated by the UWB signal is transmitted to the external device 20 via the wireless communication antenna 33, and in the wired communication mode, the wireless signal modulated by the UWB signal is externally transmitted via the cable 1. It is transmitted to the device 20.

  Further, the wireless communication unit 31 is also connected to a video signal output unit 219, and the digital video signal (DVI signal) output from the video signal output unit 219 is a signal (UWB signal) in a predetermined format such as the UWB format. And a radio signal corresponding to the converted signal (that is, a radio signal modulated by the digital video signal) can be transmitted to the external device 20. In the wireless communication mode, a wireless signal modulated by the digital video signal is transmitted to the external device 20 via the wireless communication antenna 33. In the wired communication mode, the wireless signal modulated by the digital video signal is transmitted via the cable 1. Transmitted to the external device 20.

  As described above, the wireless communication unit 31 is realized as one independent wireless module, and the above-described RF switch unit 32 can be mounted in the wireless module. The control of the RF switch unit 32 can be executed, for example, via a general purpose I / O port (GPIO) provided in the wireless communication unit 31. FIG. 3 shows an example in which the RF switch unit 32 is controlled by the control signal CONT output from the south bridge 215. For example, the control signal CONT may be supplied from the EC / KBC 218 to the RF switch unit 32. Further, by turning on / off the control signal CONT supplied to the RF switch unit 32 according to the operation of a button switch provided in the computer 10, the RF switch unit 32 can be controlled by a manual operation by the user.

  The EC / KBC 218 is a one-chip microcomputer in which an embedded controller for power management and a keyboard controller for controlling the keyboard (KB) 13 and the touch pad 16 are integrated.

  Next, an example of the system configuration of the external device 20 that functions as a wireless docking station (extension unit) will be described with reference to FIG. The system configuration of FIG. 4 corresponds to the case where a power cable is used as the cable 1.

  The external device 20 includes a hub (HUB) 70, a DVI connector 71, and USB connectors 72 and 73 in addition to the above-described wireless communication unit 41, RF switch unit 42, capacitor 61, filter 62, and power supply circuit 63.

  As described above, the wireless communication unit 41 is realized as one independent wireless module, and the above-described RF switch unit 42 can be mounted in the wireless module. The control of the RF switch unit 42 can be executed, for example, via a general purpose I / O port (GPIO) provided in the wireless communication unit 41. FIG. 4 shows an example in which the RF switch unit 42 is controlled by the control signal CONT output from the control unit 45. For example, the RF switch unit 42 is manually controlled by turning on / off the control signal CONT supplied to the RF switch unit 42 according to the operation of a button switch provided in the external device 20. You can also.

  The video connector 71 is a connector for connecting an external display device, and outputs a digital video signal received from the computer 10 by the wireless communication unit 41 to the external display device. The format of the video signal output from the video connector 71 is not particularly limited. For example, if it is necessary to output an RGB signal from the video connector 71, a circuit for converting the digital video signal received by the wireless communication unit 41 from the DVI signal to the RGB signal may be provided in the front stage of the video connector 71. .

  Each of the USB connectors 72 and 73 is a connector for connecting an external USB device. These USB connectors 72 and 73 are connected to the wireless communication unit 41 via the hub 70. Data transmission between each of the USB devices connected to the USB connectors 72 and 73 and the USB controller 301 in the computer 10 is performed via data communication between the wireless communication unit 31 and the wireless communication unit 41. Executed.

  Next, the procedure of the communication control process executed by the CPU 211 will be described with reference to the flowchart of FIG.

  First, the CPU 211 starts communication with the external device 20 in the wireless communication mode (step S11). In this step S11, the CPU 211 controls the RF switch unit 32 to connect the radio signal input / output port of the RF unit 311 in the radio communication unit 31 to the radio antenna 33, whereby the radio communication unit 31 and the external device 20 are connected. Starts wireless communication with.

  Then, the CPU 211 determines whether there is an unused frequency channel (step S12). In step S12, for example, the wireless communication unit 31 scans each of a plurality of frequency channels, and the CPU 211 determines whether there is an unused frequency channel based on the scan result.

  If there is no unused frequency channel (YES in step S12), the CPU 211 displays a message on the LCD 121 prompting the user to connect the computer 10 and the external device 20 via a cable (for example, a power cable). It is displayed on the screen (step S13). Then, the CPU 211 determines whether the cable 1 is connected to the computer 10 in cooperation with the OS or the BIOS (step S14).

  If the cable 1 is connected to the computer 10 (YES in step S14), the CPU 211 controls the RF switch unit 32 to switch the connection destination of the RF unit 311 of the wireless communication unit 31 to a wired port, thereby externally. The communication mode with the device 20 is set to the wired communication mode (step S15). As a result, the wireless communication unit 31 executes communication with the external device 20 in the wired communication mode (step S16). In step S <b> 16, the wireless signal is transmitted / received between the computer 10 and the external device 20 via the cable 1.

  When there is an unused frequency channel (YES in step S12), the CPU 211 determines whether the cable 1 is connected to the computer 10 in cooperation with the OS or the BIOS (step S17). If the cable 1 is not connected to the computer 10 (NO in step S17), the CPU 211 continues to execute communication in the wireless communication mode. On the other hand, if the cable 1 is connected to the computer 10 (YES in step S17), the CPU 211 executes a user setting process for determining a communication mode to be used in accordance with the user setting (step S18).

  In step S <b> 18, the CPU 211 determines the communication mode to be used with reference to switching setting information designated in advance by the user and indicating which of the wired communication mode and the wireless communication mode has priority. Specifically, in step S18, the CPU 211 executes the procedure shown in the flowchart of FIG. First, it is determined whether the switching setting information indicates a wired communication mode or a wireless communication mode (step S21). If the switching setting information indicates the wireless communication mode, the CPU 211 continues to execute communication in the wireless communication mode. On the other hand, if the switching setting information indicates the wired communication mode, the CPU 211 controls the RF switch unit 32 to switch the connection destination of the RF unit 311 of the wireless communication unit 31 to the wired port, thereby connecting to the external device 20. The communication mode is set to the wired communication mode (step S22). As a result, the wireless communication unit 31 executes communication with the external device 20 in the wired communication mode (step S23). In step S <b> 23, the wireless signal is transmitted / received between the computer 10 and the external device 20 via the cable 1.

  During a period in which communication with the external device 20 is being executed in the wireless communication mode, the CPU 211 determines whether or not radio wave interference has occurred in step S12 based on the packet error rate or the like. If the occurrence of radio wave interference is detected (YES in step S12), the CPU 211 executes the above-described steps after step S13 in order to switch to the wired communication mode.

  FIG. 7 shows another example of the configuration of the computer 10 and the external device 20 corresponding to the case where a power cable is used as the cable 1.

  In FIG. 7, in the computer 10, the RF switch unit 32 is connected to the power line of the power cable 1 via the first and second antennas A <b> 1 and A <b> 2 instead of the capacitor 51 of FIG. 2. Yes. These two antennas A1 and A2 have the same frequency characteristics as the wireless communication antenna 33 'and cover a frequency band of 3.1 GHz to 5.2 GHz, for example. These two antennas A1 and A2 are used for superimposing the radio signal transmitted from the radio communication unit 31 on the power line in the power cable 1 and extracting the radio signal from the power line in the power cable 1. . By using these two antennas A1 and A2, the frequency characteristic of the radio signal transmitted / received via the power cable 1 can be made the same as the frequency characteristic of the radio signal transmitted / received via the radio communication antenna 33. .

  In the present embodiment, these two antennas A1 and A2 are provided in the computer 10 in order to prevent radio waves from leaking to the outside and to prevent noise from entering other electronic components in the computer. Formed inside the printed circuit board. In this case, the computer 10 is a print in which a first antenna A1 and a second antenna A2 that is spaced apart from the first antenna A1 and opposed to the first antenna A1 are formed. A circuit board is provided. The RF switch unit 32 is connected to the first antenna A1 via the first connector on the printed circuit board. The second antenna A2 in the printed circuit board is connected to a power line in the power cable 1 via a second connector on the printed circuit board.

  Also in the external device 20, the RF switch unit 42 is connected to the power line of the power cable 1 via the first and second antennas B <b> 1 and B <b> 2 instead of the capacitor 61 of FIG. 2.

  FIG. 8 shows a configuration example of a printed circuit board with a built-in antenna provided in the computer 10.

  The printed circuit board is a multilayer wiring board having a plurality of wiring layers. The wiring layer (layer 1) of the printed circuit board includes a first connector (antenna A1 connector) connected to the first antenna A1. A second connector (antenna A2 connector) connected to the second antenna A2 is provided. The first antenna A1 is formed on the inner layer, for example, layer 2, and the second antenna A2 is formed on another inner layer, for example, layer 5. A through hole is provided between the first antenna A1 and the second antenna A2, and the first antenna A1 and the second antenna A2 face each other through the through hole.

  FIG. 9 shows another configuration example of a printed circuit board with a built-in antenna provided in the computer 10.

  The printed circuit board is a multilayer wiring board having a plurality of wiring layers. The wiring layer (layer 1) of the printed circuit board includes a first connector (antenna A1 connector) connected to the first antenna A1. A second connector (antenna A2 connector) connected to the second antenna A2 is provided. The first antenna A1 is formed in the inner layer, for example, layer 3, and the second antenna A2 is also formed in the same inner layer, for example, layer 3. The first antenna A1 and the second antenna A2 face each other.

  Note that the antennas B1 and B2 of the external device 20 can also be incorporated in the printed circuit board as shown in FIG. 8 or FIG.

  FIG. 10 shows still another example of the configuration of the computer 10 and the external device 20 corresponding to the case where a power cable is used as the cable 1.

  In FIG. 10, the computer 10 has the same configuration as that described in FIG. 2, but the external device 20 corresponds to a destination where use of a frequency band corresponding to a short-range wireless communication system such as UWB is prohibited. It has a configuration. That is, in the external device 20 of FIG. 10, although the wireless communication part 41 is mounted, the wireless communication antenna is not provided, and the wireless communication part 41 always performs communication in the wired communication mode.

  FIG. 11 shows still another example of the configuration of the computer 10 and the external device 20 corresponding to the case where a power cable is used as the cable 1.

  In FIG. 11, the external device 20 has the same configuration as that described in FIG. 2, but the computer 10 corresponds to a destination where use of a frequency band corresponding to a short-range wireless communication system such as UWB is prohibited. It has a configuration. That is, in the computer 10 of FIG. 11, the wireless communication unit 31 is mounted, but no wireless communication antenna is provided, and the wireless communication unit 31 always performs communication in the wired communication mode.

  FIG. 12 shows still another example of the configuration of the computer 10 and the external device 20 corresponding to the case where a power cable is used as the cable 1.

  In the computer 10, two wireless communication antennas 33 and 33 'are provided. In the wireless communication mode, these two wireless communication antennas 33 and 33 'function as diversity antennas.

  In the wired communication mode, the RF unit 311 of the wireless communication unit 31 is connected to the power line of the power cable 1 via the RF switch unit 32, the first antenna A 1, and the second antenna A 2. Wireless signals.

  The external device 20 is also provided with two wireless communication antennas 43 and 43 '. In the wireless communication mode, these two wireless communication antennas 43 and 43 'function as diversity antennas.

  In the wired communication mode, the RF unit 411 of the wireless communication unit 41 is connected to the power line of the power cable 1 via the RF switch unit 42, the first antenna B 1, and the second antenna B 2. Wireless signals.

  FIG. 13 shows examples of configurations of the computer 10 and the external device 20 corresponding to the case where a dedicated communication cable different from the power cable is used as the cable 1.

  In FIG. 13, reference numeral 500 denotes a communication-dedicated cable used in the wired communication mode. In the computer 10, the RF switch unit 32 is connected to the cable 500 in the wired communication mode. In the external device 20, the RF switch unit 42 is connected to the cable 500 in the wired communication mode.

  FIG. 14 shows another example of the configuration of the computer 10 and the external device 20 corresponding to a case where a dedicated communication cable different from the power cable is used as the cable 1.

  Each of the computer 10 and the external device 20 has a configuration corresponding to a destination where use of a frequency band corresponding to a short-range wireless communication system such as UWB is prohibited. That is, in the computer 10 of FIG. 14, the wireless communication unit 31 is mounted, but no wireless communication antenna is provided, and the wireless communication unit 31 always performs communication in the wired communication mode. In the wired communication mode, the wireless communication unit 31 transmits and receives wireless signals via the cable 500.

  Also in the external device 20 of FIG. 14, although the wireless communication unit 41 is mounted, the wireless communication antenna is not provided, and the wireless communication unit 41 always performs communication in the wired communication mode. In the wired communication mode, the wireless communication unit 41 transmits and receives wireless signals via the cable 500.

  As described above, according to the computer of this embodiment, the RF switch unit 32 is provided at the output stage of the wireless communication unit 31, and the communication mode with the external device 20 is set via the wireless communication antenna 33 to the external device. 20 between the external device 20 and the wireless communication unit 31 via the wireless communication mode for transmitting and receiving wireless signals between the wireless device 20 and the wireless communication unit 31 and the cable 1 connecting the external device 20 and the computer 10. It is possible to switch between wired communication modes for transmitting and receiving signals. Therefore, even when wireless communication cannot be performed due to a lack of usable frequency channels or radio wave interference, communication with the external device 20 can be performed using the same wireless signal as in the wireless communication mode. Since the wireless communication unit 31 is shared by both the wireless communication mode and the wired communication mode, communication with the external device 20 can be performed even when wireless communication cannot be performed without providing a special circuit for wired communication. Can do.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

  DESCRIPTION OF SYMBOLS 1 ... Cable, 10 ... Electronic device (computer), 20 ... External device (expansion unit), 31 ... Wireless communication part, 32 ... RF switch part, 33 ... Wireless communication antenna, 35 ... Control part, 41 ... Wireless communication part, 42: RF switch unit, 43: Wireless communication antenna, 45: Control unit.

Claims (3)

A communication unit that executes communication with an external device in a wireless communication mode or a wired communication mode;
A power supply circuit that generates operating power to be supplied to each component in the electronic device from the power supplied from the external device via a power cable;
A switch unit connected to the high frequency circuit of the communication unit, and coupling a signal input / output port of the high frequency circuit to one of a radio communication antenna and the power cable;
Controlling the switch unit to communicate with the external device, via the wireless communication antenna, the wireless communication mode for transmitting and receiving wireless signals between the high-frequency circuit and the external device, and via the power cable Control means for switching between the wired communication mode for transmitting and receiving the wireless signal between the high-frequency circuit and the external device;
Comprising
The wireless communication mode is executed using a frequency channel selected from a plurality of frequency channels, and the control unit controls the switch unit when there is no unused frequency channel among the plurality of frequency channels. And setting the communication mode with the external device to the wired communication mode. The control means prompts the user to connect the power cable to the electronic device when occurrence of radio wave interference is detected during a period in which communication with the external device is performed in the wireless communication mode. The electronic device according to claim 1, wherein a message is displayed on a display screen, the switch unit is controlled, and a communication mode with the external device is set to the wired communication mode. The control unit determines whether or not the power cable is connected to the electronic device, and when determining that the power cable is connected, performs preferential communication in the wired communication mode. The electronic device according to claim 1, wherein the electronic device is an electronic device.

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