Abstract:
Disclosed is a wireless terminal for performing independent distributed-type wireless communication with a portable wireless terminal. The wireless terminal is provided with: a channel setting section for setting a channel on which wireless communication with the portable wireless terminal is performed; a trigger receiving section for receiving a trigger; a free channel search section for searching for a free channel in response to the trigger received, and for delivering a signal, which changes the set channel in accordance with the search result, to the channel setting section; and a transmission section for transmitting to the portable wireless terminal a signal which reports the change.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation application based on a PCT Patent Application No. PCT/JP2010/066786, filed Sep. 28, 2010, whose priority is claimed on Japanese Patent Application No. 2009-244353, filed on Oct. 23, 2009, the entire content of which are hereby incorporated by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a portable wireless terminal, a wireless terminal, a wireless communication system, and a wireless communication method. 
         [0004]    2. Description of the Related Art 
         [0005]    All patents, patent applications, patent publications, scientific articles, and the like, which will hereinafter be cited or identified in the present application, will hereby be incorporated by reference in their entirety in order to describe more fully the state of the art to which the present invention pertains. 
         [0006]    Conventionally, medical diagnosis using an endoscope in the medical field has been performed. An image capturing element such as a charge coupled device (CCD) is embedded in the head of an insertion part of an endoscope scope (hereinafter referred to as a scope), and a processor performs signal processing with respect to an image capturing signal photographed by the CCD, so that it is possible to observe an image (an endoscope image) of an inside of a body through a monitor. Normally, the scope and the processor are connected to each other using a signal cable. 
         [0007]    Meanwhile, a wireless endoscope system in which the scope and the processor are connected to each other in a wireless manner has been proposed. In the wireless endoscope system, a limitation of an operation using a signal cable is reduced, resulting in the improvement of operability. Furthermore, in an electronic endoscope system in which the scope and the processor are connected to each other using a signal cable, it is necessary to isolate the scope from the processor in order to ensure stability. However, in the wireless endoscope system, since a wireless connection is established instead of an electrical connection, a configuration for the isolation is not necessary. However, in the wireless endoscope system, in order to perform reliable data communication between the processor and a plurality of wireless endoscopes or between the processor and other wireless communication devices, it is necessary to consider interference caused by wireless communication. 
         [0008]    As a countermeasure thereto, in general, an autonomous distributed wireless terminal checks a peripheral radio wave state before starting communication, selects a channel less affected by interference, and starts communication. For example, an electronic endoscope system has been known in which a processor regularly receives a report of a channel used from a scope operating nearby, stores information on the channel used, automatically assigns an unused channel when a channel assignment request signal has been received from a target scope, and uses the unused channel as a channel for the scope (for example, refer to Japanese Unexamined Patent Application, First Publication, No. 2006-271432, which will be referred to as patent document 1). 
         [0009]    In the technology disclosed in patent document 1, after a channel to be used for image transmission between the processor and the scope is set, it is not possible to change the channel. Therefore, after the channel to be used for image transmission is set once, even when a communication state of the channel set based on a peripheral radio wave condition and the like is deteriorated, communication should be continued through the channel. 
         [0010]    The present invention provides a portable wireless terminal, a wireless terminal, a wireless communication system, and a wireless communication method, by which, even after a channel to be used for communication between wireless terminals is set, it is possible to change the channel to be used for communication between the wireless terminals. 
       SUMMARY 
       [0011]    A wireless terminal performs autonomous distributed wireless communication with a portable wireless terminal. The wireless terminal includes: a channel setting unit that sets a channel to be used for wireless communication with the portable wireless terminal; a trigger receiver unit that receives a trigger; a vacant channel search unit that searches for a vacant channel according to the received trigger and sends a signal for changing the set channel to the channel setting unit based on a search result; and a transmitter unit that transmits a signal for reporting the changing to the portable wireless terminal. 
         [0012]    The channel setting unit may set the channel before a signal sent from the portable wireless terminal is received. 
         [0013]    While the wireless communication with the portable wireless terminal is being performed using the channel, the vacant channel search unit may send the signal for changing the channel to the channel setting unit. 
         [0014]    The trigger receiver unit may receive the trigger from the portable wireless terminal. 
         [0015]    The wireless terminal may be a processor device of a wireless endoscope system. 
         [0016]    A portable wireless terminal performs autonomous distributed wireless communication with a wireless terminal. The wireless terminal includes a channel setting unit that sets a channel to be used for wireless communication with the portable wireless terminal, a trigger receiver unit that receives a trigger, a vacant channel search unit that searches for a vacant channel according to the received trigger and sends a signal for changing the set channel to the channel setting unit based on a search result, and a transmitter unit that transmits a signal for reporting the change to the portable wireless terminal. The portable wireless terminal includes: a sending unit that sends a trigger to the wireless terminal, the trigger being used for allowing the wireless terminal to search for a vacant channel. 
         [0017]    The sending unit may send the trigger when the wireless communication with the wireless terminal is started. 
         [0018]    The sending unit may send the trigger while the wireless communication with the wireless terminal is being performed. 
         [0019]    The portable wireless terminal may be an endoscope scope of a wireless endoscope system. 
         [0020]    A wireless communication system in which a portable wireless terminal and a wireless terminal perform autonomous distributed wireless communication, wherein the portable wireless terminal includes: a sending unit that sends a trigger to the wireless terminal, the trigger being used for allowing the wireless terminal to search for a vacant channel, and the wireless terminal includes: a channel setting unit that sets a channel to be used for wireless communication with the portable wireless terminal; a trigger receiver unit that receives a trigger sent from the portable wireless terminal; a vacant channel search unit that searches for a vacant channel according to the received trigger and sends a signal for changing the set channel to the channel setting unit based on a search result; and a transmitter unit that transmits a signal for reporting the changing to the portable wireless terminal. 
         [0021]    The channel setting unit may set the channel before a signal sent from the portable wireless terminal is received. 
         [0022]    While the wireless communication with the portable wireless terminal using the channel is being performed, the vacant channel search unit may send the signal for changing the channel to the channel setting unit. 
         [0023]    A wireless communication method in a wireless communication system in which a portable wireless terminal and a wireless terminal perform autonomous distributed wireless communication, the wireless communication method including: a sending step in which a transmitter unit of the portable wireless terminal sends a trigger to the wireless terminal, the trigger being used for allowing the wireless terminal to search for a vacant channel; a channel setting step in which a channel setting unit of the wireless terminal sets a channel that is used for performing wireless communication with the portable wireless terminal; a trigger reception step in which a trigger receiver unit of the wireless terminal receives a trigger from the portable wireless terminal; a vacant channel search step in which a vacant channel search unit of the wireless terminal searches for a vacant channel according to the received trigger and sends a signal for changing the set channel to the channel setting unit based on a search result; and a transmission step in which a transmitter unit of the wireless terminal transmits a signal for reporting the changing to the portable wireless terminal. 
         [0024]    The channel may be set before a signal sent from the portable wireless terminal is received. 
         [0025]    The signal for changing the set channel may be sent while the wireless communication is being performed with the portable wireless terminal by using the channel. 
         [0026]    After a channel to be used for communication between wireless terminals is set, when a trigger is received, the wireless terminal of the present invention searches for vacant channels, changes the set channel based on a search result, and sends a signal for reporting a change in the channel to another wireless terminal. Consequently, even after the channel to be used for communication between the wireless terminals is set, it is possible to change the channel to be used for communication between the wireless terminals. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0027]      FIG. 1  is a schematic diagram illustrating the configuration of a wireless endoscope system in accordance with a first preferred embodiment of the present invention. 
           [0028]      FIG. 2  is a block diagram illustrating the configuration of the endoscope scope in accordance with the first preferred embodiment of the present invention. 
           [0029]      FIG. 3  is a block diagram illustrating the configuration of the processor in accordance with the first preferred embodiment of the present invention. 
           [0030]      FIG. 4  is a sequence diagram illustrating the process flows of the endoscope scope and the processor in accordance with the first preferred embodiment of the present invention. 
           [0031]      FIG. 5  is a flowchart illustrating the operation procedure of the endoscope scope in accordance with the first preferred embodiment of the present invention. 
           [0032]      FIG. 6  is a flowchart illustrating the operation procedure of the processor in accordance with the first preferred embodiment of the present invention. 
           [0033]      FIG. 7  is a block diagram illustrating the configuration of an endoscope scope in accordance with a second preferred embodiment of the present invention. 
           [0034]      FIG. 8  is a sequence diagram illustrating the process flows of the endoscope scope and the processor in accordance with the second preferred embodiment of the present invention. 
           [0035]      FIG. 9  is a flowchart illustrating the operation procedure of the endoscope scope in accordance with the second preferred embodiment of the present invention. 
           [0036]      FIG. 10  is a flowchart illustrating the operation procedure of the processor in accordance with the second preferred embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     First Preferred Embodiment 
       [0037]    Hereinafter, an autonomous distributed wireless communication system in accordance with a first preferred embodiment of the present invention will be described with reference to the accompanying drawings. In addition, the preferred embodiment will be described using a wireless endoscope system. However, the present invention is not limited thereto. For example, the present invention can be applied to an autonomous distributed wireless communication system (for example, a wireless communication system using a wireless local area network (LAN), ZigBee (a registered trademark), Bluetooth (a registered trademark), millimeter-wave radio, body area radio and the like). 
         [0038]      FIG. 1  is a schematic diagram illustrating the configuration of a wireless endoscope system (a wireless communication system) in accordance with the first preferred embodiment of the present invention. In the example illustrated in  FIG. 1 , the wireless endoscope system includes an endoscope scope  1  (a portable wireless terminal) and a processor  2  (a wireless terminal, a process apparatus). 
         [0039]    The endoscope scope  1  and the processor  2  are connected to each other in a communicable state through autonomous distributed wireless communication in which communication is performed without using a base station, an access point or the like. The endoscope scope  1  is inserted into a body cavity of a patient to photograph an image of an inside of the body cavity, and transmits the photographed image to the processor  2  in a wireless manner. The processor  2  receives the image transmitted from the endoscope scope  1  and displays the received image on a monitor. 
         [0040]    Next, the configuration of the endoscope scope  1  will be described.  FIG. 2  is a block diagram illustrating the configuration of the endoscope scope  1  in accordance with the first preferred embodiment of the present invention. In the example illustrated in  FIG. 2 , the endoscope scope  1  includes an image capturing unit  11 , a transmitter unit  12 , an antenna  13 , a receiver unit  14 , a vacant channel search request sending unit  15 , a network search unit  16 , a channel port detection unit  17 , and a channel setting unit  18 . 
         [0041]    The image capturing unit  11  photographs a body cavity to acquire an image, and performs analog/digital conversion and the like with respect to acquired image data. The transmitter unit  12  modulates and transmits a radio signal. The antenna  13  transmits and receives a radio wave. The receiver unit  14  receives and demodulates a radio signal. The vacant channel search request sending unit  15  detects a vacant channel search request (a trigger). The network search unit  16  searches for the processor  2  serving as a connection destination. The channel port detection unit  17  acquires a vacant channel search result included in a channel port received from the processor  2 . The channel setting unit  18  sets a channel to be used for the transmission/reception of a radio signal in the transmitter unit  12  and the receiver unit  14 . 
         [0042]    Next, an operation of the endoscope scope  1  after being activated will be described. After the endoscope scope  1  is powered on, the vacant channel search request sending unit  15  notifies the transmitter unit  12  and the network search unit  16  of the vacant channel search request. 
         [0043]    After the network search unit  16  has been notified of the vacant channel search request, the network search unit  16  searches for the processor  2  serving as a connection destination. In detail, the network search unit  16  searches for a channel opened by the processor  2  based on a beacon message transmitted regularly after the processor  2  opens and notifies the channel setting unit  18  of information indicating the channel opened by the processor  2 . 
         [0044]    After the network search unit  16  has been notified of the information indicating the channel opened by the processor  2 , the channel setting unit  18  sets a channel to be used for transmission/reception of a radio signal in the transmitter unit  12  and the receiver unit  14  based on the notified information. 
         [0045]    The transmitter unit  12  modulates the vacant channel search request that has been notified of by the vacant channel search request sending unit  15 , and transmits the vacant channel search request to the processor  2  using the channel set by the channel setting unit  18  through the antenna  13 . Then, the endoscope scope  1  enters a standby state until the channel port transmitted from the processor  2  is received. 
         [0046]    Next, the operation of the endoscope scope  1  when the channel port has been transmitted from the processor  2  will be described. The receiver unit  14  hands over the channel port received through the antenna  13  to the channel port detection unit  17 . The channel port detection unit  17  acquires a vacant channel search result included in the channel port, and hands over the vacant channel search result to the channel setting unit  18 . The channel setting unit  18  sets a channel instructed by the vacant channel search result in the transmitter unit  12  and the receiver unit  14 . A vacant channel will be described later. 
         [0047]    Through the above-mentioned operation, after the channel is set in the transmitter unit  12  and the receiver unit  15  of the endoscope scope  1 , the transmitter unit  12  and the receiver unit  15  of the endoscope scope  1  communicate with the processor  2  using the set channel, and transmit the image data photographed and modulated by the image capturing unit  11  to the processor  2 . 
         [0048]    Next, the configuration of the processor  2  will be described.  FIG. 3  is a block diagram illustrating the configuration of the processor  2  in accordance with the first preferred embodiment of the present invention. In the example illustrated in  FIG. 3 , the processor  2  includes an antenna  21 , a receiver unit  22 , a display unit  23 , a vacant channel search request detection unit  24  (a trigger receiver unit), a vacant channel search unit  25 , a channel port sending unit  26 , a transmitter unit  27 , and a channel setting unit  28 . 
         [0049]    The antenna  21  transmits and receives a radio wave. The receiver unit  22  receives and demodulates a radio signal. The display unit  23  performs signal processing with respect to the image data transmitted from the endoscope scope  1 , and outputs resultant data to the monitor. The vacant channel search request detection unit  24  acquires the vacant channel search request (the trigger) transmitted from the endoscope scope  2 . The vacant channel search unit  25  searches for channels, which are vacant channels not used by another apparatus. The channel port sending unit  26  modulates a channel port including a vacant channel search result and sends the channel port to the scope. The transmitter unit  27  modulates and transmits a radio signal. The channel setting unit  28  sets a channel to be used for transmission/reception of a radio signal in the receiver unit  22  and the transmitter unit  27 . 
         [0050]    Next, an operation of the processor  2  after being activated will be described. After the processor is powered on, the vacant channel search unit  25  searches for channels, which are vacant channels not used by another apparatus, through the antennal  21  and the receiver unit  22 . In addition, when a plurality of vacant channels have been detected, the vacant channel search unit  25  selects a channel with the best communication quality from the detected vacant channels. Next, the vacant channel search unit  25  notifies the channel setting unit  28  of vacant channel information which is a vacant channel search result. The channel setting unit  28  sets a channel to be used when the transmitter unit  27  and the receiver unit  22  of the processor transmit and receive a radio signal based on the notified vacant channel information. 
         [0051]    In this way, the processor  2  opens. Then, the processor  2  regularly transmits a beacon including information on a channel to be used for communication, and enters a standby state until the vacant channel search request transmitted from the endoscope scope  1  is received. In addition, in relation to the vacant channel search performed by the vacant channel search unit  25 , the vacant channel may be selected based on interference power measured in each channel, or the vacant channel may be selected based on a result obtained by measuring the number of wireless communication devices performing communication using each channel or the number of packets. 
         [0052]    Next, the operation of the processor  2  when the vacant channel search request has been transmitted from the endoscope scope  1  will be described. If the vacant channel search request transmitted from the endoscope scope  1  is received through the antenna  21  and the receiver unit, the vacant channel search request detection unit  24  gives a vacant channel search instruction to the vacant channel search unit  25 . 
         [0053]    After the vacant channel search instruction is received, the vacant channel search unit  25  searches for channels which are vacant channels not used by another apparatus. In addition, when a plurality of vacant channels have been detected, the vacant channel search unit  25  selects a channel with the best communication quality from the detected channels. Next, the vacant channel search unit  25  hands over a channel port including information on the vacant channel to the channel port sending unit  26 , and gives a channel change instruction to the channel setting unit  28  such that the channel used by the receiver unit  22  and the transmitter unit  27  is changed to the vacant channel (or the channel with the best communication quality among the vacant channels). 
         [0054]    The channel port sending unit  26  sends the channel port to the endoscope scope  1  through the transmitter unit  27  and the antenna  21 . At this time, the transmitter unit  27  performs a modulation process and a transmission process. 
         [0055]    After the channel port sending unit  26  sends the channel port, the channel setting unit  28  sets the vacant channel (or the channel with the best communication quality among the vacant channels) in the transmitter unit  27  and the receiver unit  22  based on the channel change instruction received from the vacant channel search unit  25 . 
         [0056]    Through the above-mentioned operation, after the channel is set in the transmitter unit  27  and the receiver unit  22  of the processor  2 , the transmitter unit  27  and the receiver unit  22  of the processor  2  communicate with the endoscope scope  1  using the set channel, and receive the image data transmitted from the endoscope scope  1 . Then, the display unit  23  of the processor  2  performs signal processing with respect to the received image data and outputs resultant data to the monitor. 
         [0057]    Next, the process flows of the endoscope scope  1  and the processor  2  in accordance with the first preferred embodiment will be described with reference to  FIG. 4 .  FIG. 4  is a sequence diagram illustrating the process flows of the endoscope scope  1  and the processor  2  in accordance with the first preferred embodiment of the present invention. 
         [0058]    In the example illustrated in  FIG. 4 , the processor  2  is activated (step S 101 ), performs a vacant channel search (step S 102 ), and opens by setting a channel to be used for communication with the endoscope scope  1  based on a search result (step S 103 ). Then, the processor  2  enters a standby state until the vacant channel search request transmitted from the endoscope scope  1  is received. 
         [0059]    After the processor  2  enters the standby state, the endoscope scope  1  is activated (step S 104 ), performs a network search (step S 105 ), and specifies the processor  2  serving as a connection destination and a channel to be used for communication with the processor  2  based on the beacon message regularly transmitted from the processor  2 . Next, the endoscope scope  1  sets the channel to be used for communication with the processor  2  serving as the connection destination (step S 106 ), and sends a vacant channel search request to the processor  2  serving as the connection destination (step S 107 ). Then, the endoscope scope  1  enters a standby state until the channel port transmitted from the processor  2  is received. 
         [0060]    After the vacant channel search request is received, the processor  2  performs the vacant channel search again (step S 108 ), and specifies a vacant channel. That is, the processor  2  reviews the channel selection. Next, the processor  2  transmits a channel port including information indicating the vacant channel to the endoscope scope  1  (step S 109 ), and then changes the channel used for communication with the endoscope scope  1  to the vacant channel (or the channel with the best communication quality among the vacant channels) (step S 110 ). Meanwhile, after the channel port is received, the endoscope scope  1  also changes the channel used for communication with the processor  2  to the vacant channel (or the channel with the best communication quality among the vacant channels) based on the received channel port (step S 110 ). 
         [0061]    In this way, after the channel to be used between the endoscope scope  1  and the processor  2  is set, the endoscope scope  1  and the processor  2  start to communicate with each other (step S 111 ). 
         [0062]    Next, the operation procedure of the endoscope scope  1  in accordance with the first preferred embodiment will be described.  FIG. 5  is a flowchart illustrating the operation procedure of the endoscope scope  1  in accordance with the first preferred embodiment of the present invention. 
       (Step S 201 ) 
       [0063]    The endoscope scope  1  is activated. Then, the procedure proceeds to the process of step S 202 . 
       (Step S 202 ) 
       [0064]    The network search unit  16  performs network search, and specifies the processor  2  serving as a connection destination and a channel to be used for communication with the processor  2  based on the beacon message regularly transmitted from the processor  2 . Then, the procedure proceeds to the process of step S 203 . 
       (Step S 203 ) 
       [0065]    The channel setting unit  18  sets the channel to be used for communication with the processor  2  serving as the connection destination specified in step S 202 . Then, the procedure proceeds to the process of step S 204 . 
       (Step S 204 ) 
       [0066]    The vacant channel search request sending unit  15  sends a vacant channel search request to the processor  2  serving as the connection destination determined in step S 202  using the channel set in the process of step S 203 . Then, the procedure proceeds to the process of step S 205 . 
       (Step S 205 ) 
       [0067]    If the channel port detection unit  17  receives the channel port from the processor  2 , the channel port detection unit  17  proceeds to the process of step S 206 . Otherwise, the channel port detection unit  17  performs the process of step S 205  again. That is, the channel port detection unit  17  waits until the channel port is received. 
       (Step S 206 ) 
       [0068]    The channel setting unit  18  sets the vacant channel (or the channel with the best communication quality among the vacant channels) included in the channel port in the transmitter unit  12  and the receiver unit  14 . Then, the procedure proceeds to the process of step S 207 . 
       (Step S 207 ) 
       [0069]    The endoscope scope  1  starts to communicate with the processor  2 . 
         [0070]    Next, the operation procedure of the processor  2  in accordance with the first preferred embodiment will be described.  FIG. 6  is a flowchart illustrating the operation procedure of the processor  2  in accordance with the first preferred embodiment of the present invention. 
       (Step S 301 ) 
       [0071]    The processor  2  is activated. Then, the procedure proceeds to the process of step S 302 . 
       (Step S 302 ) 
       [0072]    The vacant channel search unit  25  performs a vacant channel search and specifies the vacant channel (or the channel with the best communication quality among the vacant channels). Then, the procedure proceeds to the process of step S 303 . 
       (Step S 303 ) 
       [0073]    The channel setting unit  28  sets the vacant channel (or the channel with the best communication quality among the vacant channels) specified in step S 302  in the transmitter unit  27  and the receiver unit  22 . In this way, the processor  2  opens. Then, the procedure proceeds to the process of step S 304 . 
       (Step S 304 ) 
       [0074]    If the vacant channel search request detection unit  24  receives the vacant channel search request from the endoscope scope  1 , the vacant channel search request detection unit  24  proceeds to the process of step S 305 . Otherwise, the vacant channel search request detection unit  24  performs the process of step S 304 . That is, the vacant channel search request detection unit  24  waits until the vacant channel search request is received. 
       (Step S 305 ) 
       [0075]    The vacant channel search unit  25  performs a vacant channel search and specifies a vacant channel. In addition, when a plurality of vacant channels have been detected, the vacant channel search unit  25  selects a channel with the best communication state. Furthermore, the vacant channel search unit  25  hands over the channel port including the information on the vacant channel to the channel port sending unit  26 . Then, the procedure proceeds to the process of step S 306 . 
       (Step S 306 ) 
       [0076]    The channel port sending unit  26  sends the channel port to the endoscope scope  1 . Then, the procedure proceeds to the process of step S 307 . 
       (Step S 307 ) 
       [0077]    The channel setting unit  18  sets the vacant channel (or the channel with the best communication quality among the vacant channels) detected by the vacant channel search unit  25  in step S 305  in the transmitter unit  12  and the receiver unit  14 . Then, the procedure proceeds to the process of step S 308 . 
       (Step S 308 ) 
       [0078]    The processor  2  starts to communicate with the endoscope scope  1 . 
         [0079]    As described above, the processor  2  of the first preferred embodiment is activated and then sets the channel to be used for communication with the endoscope scope  1 . Furthermore, the endoscope scope  1  is activated and then transmits the vacant channel search request to the processor  2 . Furthermore, after the vacant channel search request is received, the processor  2  searches vacant channels, sets a channel again to be used for communication with the endoscope scope  1  based on a search result, and transmits a channel port including information on a changed channel to the endoscope scope  1 . Furthermore, the endoscope scope  1  sets a channel to be used for communication with the processor  2  based on the channel port. 
         [0080]    In this way, after the processor  2  is activated, even when a wireless communication environment is changed by the time the endoscope scope  1  is activated, the processor  2  searches for vacant channels again at a timing appropriate for a user, for example, at the time of communication start or power-on of the scope. Consequently, it is possible for the processor  2  to assign a channel optimal for communication, so that the endoscope scope  1  and the processor  2  can communicate with each other using the optimal channel. 
       Second Preferred Embodiment 
       [0081]    Hereinafter, a second preferred embodiment of the present invention will be described with reference to the accompanying drawings. In addition, the configuration of a processor  2  in accordance with the second preferred embodiment is similar to that of the processor  2  in accordance with the first preferred embodiment. 
         [0082]    Next, the configuration of an endoscope scope  1  in accordance with the second preferred embodiment will be described.  FIG. 7  is a block diagram illustrating the configuration of an endoscope scope  1  in accordance with the second preferred embodiment of the present invention. The configuration of the endoscope scope  1  in accordance with the second preferred embodiment is substantially identical to the configuration of the endoscope scope  1  in accordance with the first preferred embodiment, except that the endoscope scope  1  in accordance with the second preferred embodiment includes an event detection unit  19 . 
         [0083]    In the example illustrated in  FIG. 7 , the endoscope scope  1  includes an image capturing unit  11 , a transmitter unit  12 , an antenna  13 , a receiver unit  14 , a vacant channel search request sending unit  15 , a network search unit  16 , a channel port detection unit  17 , a channel setting unit  18 , and the event detection unit  19 . In addition, the image capturing unit  11 , the transmitter unit  12 , the antenna  13 , the receiver unit  14 , the vacant channel search request sending unit  15 , the network search unit  16 , the channel port detection unit  17 , and the channel setting unit  18  in accordance with the second preferred embodiment are identical to those in accordance with the first preferred embodiment. 
         [0084]    The event detection unit  19  detects an event for starting diagnosis occurring in the endoscope scope  1 , and notifies the vacant channel search request sending unit  15  of information indicating the detection of the event for starting diagnosis. After the information indicating the detection of the event for starting diagnosis has been notified of, the vacant channel search request sending unit  15  transmits a vacant channel search request to the processor  2  through the transmitter unit  12  and the antenna  13 . 
         [0085]    In addition, the event for starting diagnosis corresponds to a process which is performed before starting diagnosis. For example, in relation to the detection of the event for starting diagnosis, switch pressing of white balance adjustment of an image necessarily performed before diagnosis may be detected, the pressing of a dedicated switch for setting a channel again by a surgical operator may be detected, a result obtained by detecting the recognition of a scope by a surgical operator through a switch or a sensor may be acquired, or input of patient information for starting diagnosis may be detected. Furthermore, it may be possible to acquire location information using GPS and the like to detect entrance to a diagnosis room, to detect that the distance between the processor  2  and the endoscope scope  1  is less than or equal to a constant value using a laser or a communication device with a short communication distance, or to detect that a constant time has passed since the endoscope scope  1  was powered on. 
         [0086]    Next, the process flows of the endoscope scope  1  and the processor  2  in accordance with the second preferred embodiment will be described with reference to  FIG. 8 .  FIG. 8  is a sequence diagram illustrating the process flows of the endoscope scope  1  and the processor  2  in accordance with the second preferred embodiment of the present invention. 
         [0087]    Hereinafter, since the processes of step S 401  to step S 411  in accordance with the second preferred embodiment are identical to the processes of step S 101  to step S 111  in accordance with the first preferred embodiment, description thereof will be omitted. 
         [0088]    In the example illustrated in  FIG. 8 , since processes after the endoscope scope  1  and the processor  2  start to communicate with each other, that is, processes after step S 412 , are added, the processes after step S 412  will be sequentially described. 
         [0089]    After starting to communicate with the processor  2 , when the event detection unit  19  has detected an event for starting diagnosis (step S 412 ), the endoscope scope  1  sends a vacant channel search request to the processor  2  (step S 413 ). 
         [0090]    After the vacant channel search is received, the processor  2  performs a vacant channel search again (step S 414 ) and specifies a vacant channel. In addition, when a plurality of vacant channels have been detected, the vacant channel search unit  25  selects a channel with the best communication quality. That is, the processor  2  reviews channel selection. 
         [0091]    Next, the processor  2  transmits a channel port including information indicating the vacant channel to the endoscope scope  1  (step S 415 ), and then changes a channel used for communicating with the endoscope scope  1  to the vacant channel (or the channel with the best communication quality among the vacant channels) (step S 416 ). Meanwhile, after the channel port is received, the endoscope scope  1  also changes a channel used for communicating with the processor  2  to the vacant channel (or the channel with the best communication quality among the vacant channels) based on the received channel port (step S 416 ). 
         [0092]    Next, the operation procedure of the endoscope scope  1  in accordance with the second preferred embodiment will be described.  FIG. 9  is a flowchart illustrating the operation procedure of the endoscope scope  1  in accordance with the second preferred embodiment of the present invention. 
         [0093]    Hereinafter, since the processes of step S 501  to step S 507  in accordance with the second preferred embodiment are identical to the processes of step S 201  to step S 207  in accordance with the first preferred embodiment, description thereof will be omitted. 
         [0094]    In the example illustrated in  FIG. 9 , since processes after the endoscope scope  1  and the processor  2  start to communicate with each other, that is, processes after step S 508 , are added, the processes after step S 508  will be sequentially described. 
       (Step S 508 ) 
       [0095]    While the endoscope scope  1  and the processor  2  are communicating with each other, if the event detection unit  19  has detected an event for starting diagnosis, the event detection unit  19  proceeds to the process of step S 509 . Otherwise, the event detection unit  19  performs the process of step S 508  again. That is, the endoscope scope  1  waits until the event detection unit  19  detects the event for starting diagnosis. 
       (Step S 509 ) 
       [0096]    The vacant channel search request sending unit  15  sends a vacant channel search request to the processor  2 . Then, the procedure proceeds to the process of step S 510 . 
       (Step S 510 ) 
       [0097]    If the channel port detection unit  17  receives the channel port from the processor  2 , the channel port detection unit  17  proceeds to the process of step S 511 . Otherwise, the channel port detection unit  17  performs the process of step S 510  again. That is, the channel port detection unit  17  waits until the channel port is received. 
       (Step S 511 ) 
       [0098]    The channel setting unit  18  sets the vacant channel (or the channel with the best communication quality among the vacant channels) included in the channel port in the transmitter unit  12  and the receiver unit  14 . 
         [0099]    Next, the operation procedure of the processor  2  in accordance with the second preferred embodiment will be described.  FIG. 10  is a flowchart illustrating the operation procedure of the processor  2  in accordance with the second preferred embodiment of the present invention. 
         [0100]    Hereinafter, since the processes of step S 601  to step S 608  in accordance with the second preferred embodiment are identical to the processes of step S 301  to step S 308  in accordance with the first preferred embodiment, description thereof will be omitted. 
         [0101]    In the example illustrated in  FIG. 10 , since processes after the processor  2  and the endoscope scope  1  start to communicate with each other, that is, processes after step S 609 , are added, the processes after step S 609  will be sequentially described. 
       (Step S 609 ) 
       [0102]    If the vacant channel search request detection unit  24  receives the vacant channel search request from the endoscope scope  1 , the vacant channel search request detection unit  24  proceeds to the process of step S 610 . Otherwise, the vacant channel search request detection unit  24  performs the process of step S 609  again. That is, the vacant channel search request detection unit  24  waits until the vacant channel search request is received. 
       (Step S 610 ) 
       [0103]    The vacant channel search unit  25  performs a vacant channel search and specifies a vacant channel. In addition, when a plurality of vacant channels have been detected, the vacant channel search unit  25  selects a channel with the best communication state. Furthermore, the vacant channel search unit  25  hands over a channel port including information on the vacant channel to the channel port sending unit  26 . Then, the procedure proceeds to the process of step S 611 . 
       (Step S 611 ) 
       [0104]    The channel port sending unit  26  sends the channel port to the endoscope scope  1 . Then, the procedure proceeds to the process of step S 612 . 
       (Step S 612 ) 
       [0105]    The channel setting unit  18  sets the vacant channel (or the channel with the best communication quality among the vacant channels) detected by the vacant channel search unit  25  in step S 610  in the transmitter unit  12  and the receiver unit  14 . 
         [0106]    As described above, before diagnosis actually starts, the endoscope scope  1  in accordance with the second preferred embodiment transmits the vacant channel search request to the processor  2  again. Furthermore, after the vacant channel search request is received, the processor  2  searches vacant channels, sets a channel again to be used for communication with the endoscope scope  1  based on a search result, and transmits a channel port including information on a changed channel to the endoscope scope  1 . Furthermore, the endoscope scope  1  sets a channel to be used for communication with the processor  2  based on the channel port. 
         [0107]    Consequently, for example, when a surgical operator activates the endoscope scope  1  in a management area and then moves into a diagnosis room with the endoscope scope  1  in his or her hand, it is possible to search for vacant channels again at the time and place where diagnosis actually starts and assign an optical channel, so that the endoscope scope  1  and the processor  2  can communicate with each other using the optical channel. 
         [0108]    In addition, in the flowcharts illustrated in  FIGS. 9 and 10 , the event detection process and the vacant channel search process are performed only once as the processes after communication starts. However, the event detection process and the vacant channel search process may be repeated in a loop twice or more. In detail, in the flowchart illustrated in  FIG. 9 , the processes from step S 508  to step S 511  may be repeated. Furthermore, in the flowchart illustrated in  FIG. 10 , the processes from step S 609  to step S 612  may be repeated. 
         [0109]    While the first and second preferred embodiments of the present invention have been described and illustrated above, it should be understood that these are examples of the present invention and are not to be considered as limiting. Additions, omissions, substitutions, and other modifications can be made without departing from the scope of the present invention. Accordingly, the invention is not to be considered as being limited by the foregoing description, and is only limited by the scope of the claims. 
         [0110]    For example, in the first and second preferred embodiments, the wireless endoscope system provided with one endoscope scope  1  has been described as an example. However, the present invention is not limited thereto. For example, the present invention can be applied to a wireless endoscope system provided with a plurality of endoscope scopes  1 . 
         [0111]    Furthermore, as described above, the endoscope scope  1  and the processor  2  in accordance with the first and second preferred embodiments can avoid interference without a wireless communication unit (for example, an RFID tag reader, an RFID and the like) different from a wireless communication unit for image data transmission. Consequently, it is possible to avoid crosstalk without an apparatus becoming more expensive. That is, as an additional effect, it is possible to avoid crosstalk without an apparatus becoming more expensive. 
         [0112]    The wireless terminal of the present invention can set a channel to be used for communication between wireless terminals and then change the channel to be used for communication between the wireless terminals, so that it is possible to perform reliable communication using a plurality of wireless terminals.