Patent Publication Number: US-2021195323-A1

Title: Cable apparatus, noise cancelling apparatus, and noise cancelling method

Description:
TECHNICAL FIELD 
     The present technique relates to a cable apparatus, a noise canceling apparatus, and a noise canceling method, and in particular, to a cable apparatus, a noise canceling apparatus, and a noise canceling method enabled to reliably remove noise induced by a radio wave. 
     BACKGROUND ART 
     In recent years, IoT (Internet of Things) has been remarkably developed, and various types of wireless communication functions are provided in every IoT device from various products to infrastructure equipment. These IoT devices generally have a function of loading information (analog information) from an outside world and outputting the information. In other words, the IoT device is generally assumed to deal with every signal from high-frequency radio signals to low-frequency analog signals. Here, analog signals generally have low noise immunity, and thus, noise induced by a radio wave is non-negligible. 
     For example, PTL 1 discloses a technique in which, in addition to a first microphone acquiring voice emitted by a speaker, a second microphone acquiring noise is provided to remove a noise signal acquired by the second microphone from a voice signal acquired by the first microphone. 
     CITATION LIST 
     Patent Literature 
     
         
         [PTL 1] 
       
    
     JP 2009-188858 A 
     SUMMARY 
     Technical Problem 
     However, the technique disclosed in PTL 1 described above cannot remove noise induced by the radio wave and is thus far from taking sufficient countermeasures for preventing noise. 
     In view of these circumstances, an object of the present technique is to allow reliable removal of the noise induced by the radio wave. 
     Solution to Problem 
     A cable apparatus according to a first aspect of the present technique is a cable apparatus including wiring for input which is electrically connected to a device and through which an input signal and an RF noise signal induced are transmitted, and wiring for noise detection which is electrically connected to an adjustment element enabled to be adjusted to an impedance corresponding to an input impedance of an output circuit of the device and in which the RF noise signal is induced. 
     The cable apparatus according to the first aspect of the present technique is provided with the wiring for input which is electrically connected to the device and through which the input signal and the RF noise signal induced are transmitted and the wiring for noise detection which is electrically connected to the adjustment element enabled to be adjusted to the impedance corresponding to the input impedance of the output circuit of the device and in which the RF noise signal is induced. 
     A noise canceling apparatus according to a second aspect of the present technique is a noise canceling apparatus including a signal processing section configured to remove a noise signal to an input signal transmitted through wiring for input electrically connected to a device, using an RF noise signal induced in wiring for noise detection electrically connected to an adjustment element enabled to be adjusted to an impedance corresponding to an input impedance of an output circuit of the device. 
     A noise canceling method according to the second aspect of the present technique is a noise canceling method corresponding to the noise canceling apparatus according to the second aspect of the present technique described above. 
     In the noise canceling apparatus and the noise canceling method according to the second aspect of the present technique, the RF noise signal to the input signal transmitted through the wiring for input electrically connected to the device is removed using the RF noise signal induced in the wiring for noise detection electrically connected to the adjustment element enabled to be adjusted to the impedance corresponding to the input impedance of the output circuit of the device. 
     The cable apparatus according to the first aspect of the present technique and the noise canceling apparatus according to the second aspect of the present technique may be independent apparatuses or internal blocks forming one apparatus. 
     Advantageous Effect of Invention 
     According to the first aspect and the second aspect of the present technique, noise induced by a radio wave can be reliably removed. 
     Note that the effects described here are not necessarily limited and that any of the effects described in the present disclosure may be produced. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a diagram illustrating the principle of generation of radio wave noise. 
         FIG. 2  is a diagram illustrating an example of a configuration of a general noise canceling system. 
         FIG. 3  is a diagram illustrating a configuration example of an embodiment of a noise canceling system to which the present technique is applied. 
         FIG. 4  is a diagram illustrating a first example of a configuration of the noise canceling system to which the present technique is applied. 
         FIG. 5  is a diagram illustrating a second example of a configuration of the noise canceling system to which the present technique is applied. 
         FIG. 6  is a diagram illustrating a third example of a configuration of the noise canceling system to which the present technique is applied. 
         FIG. 7  is a diagram illustrating a fourth example of a configuration of a noise canceling system to which the present technique is applied. 
         FIG. 8  is a diagram illustrating an example of a configuration of a computer. 
         FIG. 9  is a view depicting an example of a schematic configuration of an endoscopic surgery system. 
         FIG. 10  is a block diagram depicting an example of a functional configuration of a camera head and a camera control unit (CCU) depicted in  FIG. 9 . 
     
    
    
     DESCRIPTION OF EMBODIMENT 
     An embodiment of the present technique will be described with reference to the drawings. Note that the description will be in the following order.
     1. Embodiment of Present Technique   2. Modified Example   3. Configuration of Computer   4. Applied Example   

     &lt; 1 . Embodiment of Present Technique&gt; 
       FIG. 1  is a diagram illustrating the principle of generation of radio noise. 
     In  FIG. 1 , a noise canceling system includes a sensor  911 , a signal processing circuit  913  including an input circuit  941 , and a signal line  951  and a ground line  952  through which electric signals from the sensor  911  are transmitted to (the input circuit  941  of) the signal processing circuit  913 . 
     The sensor  911  is adjusted to a frequency band f A  for target information (desired information) and can detect the target information. Additionally, here, the sensor  911 , the signal line  951 , and the ground line  952  form a circuit network  900 . 
     In a case where such a configuration is employed, the circuit network  900  behaves like an antenna for a frequency band f B  corresponding to a frequency band higher than the frequency band f A . Specifically, as illustrated in  FIG. 1 , in a case where a transmission source  200  for radio waves that performs wireless communication using the frequency band f B  is present near the circuit network  900 , the circuit network  900  induces a signal S B1  in addition to a signal S A1  corresponding to the target information. 
     Here, as illustrated at a portion A in  FIG. 1 , in the wireless communication (frequency band f B ) performed by the transmission source  200 , a first period T 1  during which a radio wave is transmitted and a second period T 2  during which no radio wave is transmitted are repeatedly present in a time domain in accordance with a predetermined communication scheme. Thus, in the signal line  951  and the ground line  952 , the first period T 1 , during which the signal S B1  is generated that is induced by the wireless communication performed by the transmission source  200 , and the second period T 2 , during which the signal S B1  is not generated, are repeatedly present in the time domain. 
     Additionally, in the signal processing circuit  913 , input characteristics of the input circuit  941  are not completely linear, and thus, the signal obtained by the input circuit  941  has a difference in DC level between the first period T 1  and the second period T 2 . The frequency characteristic of a signal S C1  resulting from repetition of the first period T 1  and the second period T 2  corresponds to a frequency band f C  (for example, a portion B in  FIG. 1 ) lower than the frequency band f B . 
     Depending on the combination of the first period T 1  and the second period T 2 , the frequency band f C  is included in the frequency band f A . In a case where the frequency band f C  is included in the frequency band f A , the signal S C1 , including unnecessary information, is superimposed on the signal S A1  corresponding to the target information, causing the signal S C1  to appear as noise. 
     As a countermeasure against such noise, it is assumed that a filter for reducing the frequency band f B  (for example, a low pass filter or the like) is provided between the circuit network  900  and the input circuit  941  of the signal processing circuit  913 , thereby reducing the signal S C1 . 
     However, in a case where a configuration provided with such a filter is employed, the input circuit  941  is generally equipped with an amplifier for amplifying the signal S A1  subjected to a conversion by the sensor  911 , and thus, the signal S C1  in the frequency band f C  included in the frequency band f A  is amplified by the amplifier, similarly to the signal S A1 . Thus, the filter is required to provide a very large amount of attenuation. 
     Additionally, the intensity of the signal S C1  to be removed varies significantly depending on a positional relation between the circuit network  900  and the transmission source  200  for radio waves that performs wireless communication, the radio field intensity of the wireless communication, and the like, and thus, when the filter is set, the required amount of attenuation cannot be clearly defined. 
     As described above, a configuration with the filter interposed between the circuit network  900  and the input circuit  941  of the signal processing circuit  913  is insufficient to serve as the countermeasure against noise. 
     Additionally, PTL 1 described above discloses a configuration which is provided with a second microphone acquiring noise in addition to a first microphone acquiring voice emitted by a speaker and in which a noise signal acquired by the second microphone is removed from a voice signal acquired by the first microphone. 
     Specifically, this noise cancelation technique removes a signal S A2  (noise) obtained by a second sensor (second microphone) from a signal S A1  (signal+noise) obtained by a first sensor (first microphone). Additionally, here, as the first sensor (first microphone) and the second sensor (second microphone), sensors (microphones) dealing with the same frequency (frequency band f A ) are used. 
     Meanwhile, as illustrated in  FIG. 2 , in a case where the configuration illustrated in  FIG. 1  is applied to the configuration disclosed in PTL 1, the signal S B1  and a signal S B2  induced by the transmission source  200  (frequency band f B ) described above are phenomena resulting from the behavior, as antennas, of a circuit network  900 - 1  corresponding to a system including a sensor  911 - 1  and wiring  912 - 1  and a circuit network  900 - 2  corresponding to a system including a sensor  911 - 2  and wiring  912 - 2 . 
     The signal S B1  and the signal S B2  resulting from such phenomena are not referred to in PTL 1, and furthermore, the configuration disclosed in PTL 1 fails to exclusively remove the signal S B1  superimposed on the signal S A1 . 
     Note that, as a countermeasure against the behavior of the circuit network  900  as an antenna, also assumed is a method in which the signal line  951  and the ground line  952  in the circuit network  900  have a twisted pair structure to reduce the efficiency of the frequency band f B  when the circuit network  900  behaves as an antenna. Here, the twisted pair structure is a structure including two signal lines twisted into a pair and having a feature of being less susceptible to noise than simple parallel lines. 
     However, in the circuit network  900 , in a case where the signal line  951  and the ground line  952  have a twisted pair structure, the frequency characteristic resulting from the behavior of the circuit network  900  as an antenna is varied by a peripheral structure of the signal line  951  and the ground line  952  (for example, in a case where a metal or the like approaches), leading to a wiring constraint. Thus, the employment of the twisted pair structure is insufficient to serve as a countermeasure against noise induced by a radio wave. 
     Since the countermeasure against noise resulting from the behavior of the circuit network as an antenna is insufficient as described above, a technique for reliably removing the noise induced by the radio wave has been desired. In view of this, in the present technique (technique according to the present disclosure), an adjustment element designed under predetermined conditions for the circuit network is provided to allow reliable removal of noise resulting from the behavior of the circuit network as an antenna. An embodiment of the present technique will be described. In the following description, the noise is assumed to include, for example, RF noise, interference, and the like. 
     (Configuration of Present Technique) 
       FIG. 3  is a diagram illustrating an example of a configuration of an embodiment of a noise canceling system to which the present technique is applied. 
     In  FIG. 3 , a noise canceling system  10  includes a cable apparatus  11  and a noise canceling apparatus  12 . 
     The cable apparatus  11  includes a device  111 , wiring  112 - 1  electrically connected to the device  111 , and wiring  112 - 2  electrically connected to an adjustment element  131 . 
     The device  111  is configured as a sensor, an output apparatus outputting analog signals, or the like, for example. The device  111  includes an output circuit  121 . The output circuit  121  is electrically connected to the wiring  112 - 1 . 
     The adjustment element  131  can adjust to an impedance corresponding to an input impedance of the output circuit  121  of the device  111  and is electrically connected to the wiring  112 - 2 . The adjustment element  131  includes at least one of, for example, a fixed resistor, a capacitor, or an inductor. 
     The noise canceling apparatus  12  includes a signal processing circuit  113 . 
     The signal processing circuit  113  includes, for example, a processor such as a microprocessor. The signal processing circuit  113  is electrically connected to each of the wiring  112 - 1  and the wiring  112 - 2  of the cable apparatus  11 . The signal processing circuit  113  uses a signal from the wiring  112 - 2  to remove (cancel) noise included in a signal from the wiring  112 - 1  and outputs the resultant signal to a succeeding circuit (not illustrated). 
     Note that the configuration illustrated in  FIG. 3  is an example and that the signal processing circuit  113  may be included on the cable apparatus  11  side or that the device  111  and the wiring  112 - 1 , and the adjustment element  131  and the wiring  112 - 2  may be included on the noise canceling apparatus  12  side. Furthermore, for example, the device  111  and the adjustment element  131  may be omitted from the cable apparatus  11 , in other words, the wiring  112 - 1  and the wiring  112 - 2  may form the cable apparatus  11 . 
     The noise canceling system  10  configured as described above is provided with the adjustment element  131  designed under the predetermined conditions for the circuit network, to remove noise resulting from the behavior of the circuit network as an antenna. Now, a detailed configuration of the noise canceling system  10  will be described with reference to  FIGS. 4 to 7 . 
     (First Example of Configuration of Present Technique) 
       FIG. 4  is a diagram illustrating a first example of a configuration of the noise canceling system to which the present technique is applied. 
     In  FIG. 4 , the noise canceling system  10  includes the device  111 , the wiring  112 - 1 , the wiring  112 - 2 , the signal processing circuit  113 , and the adjustment element  131 . 
     The device  111  includes the output circuit  121 . The signal processing circuit  113  includes an input circuit  141 - 1  and an input circuit  141 - 2 . Additionally, the wiring  112 - 1  includes a signal line  151 - 1  and a ground line  152 - 1 , and the wiring  112 - 2  includes a signal line  151 - 2  and a ground line  152 - 2 . 
     The (output circuit  121  of the) device  111  is connected to (the input circuit  141 - 1  of) the signal processing circuit  113  via the wiring  112 - 1 . The adjustment element  131  is connected to the (input circuit  141 - 2  of the) signal processing circuit  113  via the wiring  112 - 2 . 
     Additionally, in the noise canceling system  10 , the device  111  and the wiring  112 - 1  form a circuit network  100 - 1 , and the adjustment element  131  and the wiring  112 - 2  form a circuit network  100 - 2 . 
     The device  111  is an apparatus that is adjusted to the frequency band f A  for target information and that processes a signal corresponding to the target information and outputs the processed signal. The device  111  can include, for example, any of various sensor devices, a circuit outputting analog signals (analog output circuit), or the like. 
     The adjustment element  131  is an element for acquiring noise resulting from a radio wave transmitted by wireless communication (frequency band f B ) performed by the transmission source  200 . Here, the adjustment element  131  is designed to output no signals in the frequency band f A  corresponding to an output from the (output circuit  121  of the) device  111  and to have, for the frequency band f B , electrical characteristics corresponding to the device  111 . 
     For example, in a case where the device  111  is a microphone dealing with a voice band and assumed wireless communication is in a 2.4-GHz band, the adjustment element  131  is configured using an element such as a fixed resistor, a capacitor, or an inductor such that the voice band is not converted into an electric signal and that, in the 2.4-GHz band, the adjustment element  131  has electrical characteristics similar to those of the microphone. 
     Specifically, an equivalent circuit having an impedance Z2 (frequency band f B ) corresponding to an input impedance Z1 (frequency band f B ) of the output circuit  121  of the device  111  is configured as the adjustment element  131  in such a manner as to provide the circuit network  100 - 1  and the circuit network  100 - 2  with similar frequency characteristics (the same frequency characteristic or corresponding frequency characteristics) with respect to the frequency band f B , as viewed from the succeeding signal processing circuit  113 . 
     Note that, in  FIG. 4 , the circuit network  100 - 1  and the circuit network  100 - 2  are assumed to lie within the reachable range of a radio wave to be transmitted by the wireless communication (frequency band f B ) performed by the transmission source  200 . 
     In a case where the circuit network  100 - 1  including the device  111  outputting the signal S A1  (frequency band f A ) corresponding to the target information and the circuit network  100 - 2  including the adjustment element  131  for acquiring noise are designed to have similar frequency characteristics when the circuit networks behave as antennas in the frequency band f B , as described above, a signal to be output from the adjustment element  131  corresponds to noise generated by the wireless communication and does not contain the signal S A1  in the frequency band f A . 
     In other words, in the noise canceling system  10 , the wiring  112 - 1  included in the circuit network  100 - 1  is used as wiring for input through which an input signal and induced RF noise are transmitted, whereas the wiring  112 - 2  included in the circuit network  100 - 2  is used as wiring for noise detection in which RF noise is induced. 
     The signal processing circuit  113  is a circuit executing signal processing for removing noise. The signal processing circuit  113  includes the input circuit  141 - 1  and the input circuit  141 - 2 . 
     In a case where the input circuit  141 - 1  is connected to the wiring  112 - 1  and lies within the reachable range of a radio wave from the transmission source  200 , a signal including the signal S C1  superimposed on the signal S A1  is input to the input circuit  141 - 1 . Additionally, in a case where the input circuit  141 - 2  is connected to the wiring  112 - 2  and lies within the reachable range of a radio wave from the transmission source  200 , a signal S C2  is input to the input circuit  141 - 2 . 
     The signal processing circuit  113  can acquire the signal S A1  corresponding to the target information by using the signal S C2  obtained by the input circuit  141 - 2  to remove the signal S C1  superimposed on the signal S A1  obtained by the input circuit  141 - 1 . 
     Specifically, as described in the principle above, in accordance with the predetermined communication scheme, the first period T 1  during which radio waves are transmitted and the second period T 2  during which no radio wave is transmitted are repeatedly present in the time domain. Additionally, the frequency characteristic of the signal S C1  resulting from the repetition of the first period T 1  and the second period T 2  corresponds to the frequency band f C , which is lower than the frequency band f B , and depending on the combination of the first period T 1  and the second period T 2 , the frequency band f C  is included in the frequency band f A . 
     In the input circuit  141 - 1  connected to the wiring  112 - 1 , in a case where the frequency band f C  is included in the frequency band f A , the signal S C1 , including unnecessary information, is superimposed on the signal S A1  corresponding to the target information, and as a result, the resultant signal appears as noise. In contrast, the input circuit  141 - 2  connected to the wiring  112 - 2  obtains the signal S C2  corresponding to the noise, and thus, the signal processing circuit  113  can remove the signal S C1  superimposed on the signal S A1  from the wiring  112 - 1 , by using the signal S C2  from the wiring  112 - 2 . 
     Note that the signal induced by the wireless communication (the amount of noise) varies depending on the transmission source  200  of radio wave and the positional relation between the circuit network  100 - 1  and the circuit network  100 - 2 , and thus, (the wiring  112 - 1  in) the circuit network  100 - 1  and (the wiring  112 - 2  in) the circuit network  100 - 2  are desirably disposed in proximity to each other (arrow D in the figure) such that the signal S C1  from the wiring  112 - 1  becomes equivalent to the signal S C2  from the wiring  112 - 2 . 
     In this case, for example, the wiring  112 - 1  and the wiring  112 - 2  can be combined into one cable. Additionally, for example, the wiring  112 - 1  and the wiring  112 - 2  may be disposed parallel to each other. Furthermore, preferably, the wiring  112 - 1  and the wiring  112 - 2  have corresponding structures, for example, have substantially the same length and substantially the same characteristics. 
     Additionally, in the frequency band f B , a difference in characteristics between the input impedance Z 1  of the (output circuit  121  of the) device  111  and the impedance Z 2  configured by the adjustment element  131  can be absorbed by parameters processed by the signal processing circuit  113 . Similarly, a difference in characteristics between the input circuit  141 - 1  and the input circuit  141 - 2  and a difference in arrangement between the circuit network  100 - 1  and the circuit network  100 - 2  can also be absorbed by the parameters of the signal processing circuit  113 . 
     (Second Example of Configuration of Present Technique) 
       FIG. 5  is a diagram illustrating a second example of a configuration of the noise canceling system to which the present technique is applied. 
     The noise canceling system  10  can be provided, as the device  111 , with any of various sensor devices, for example, a microphone, an illuminometer, a thermometer, a hygrometer, an angle sensor, an acceleration sensor, an image sensor, and the like.  FIG. 5  illustrates such a configuration that a microphone  111 A is provided as the device  111 . 
     In  FIG. 5 , the input impedance Z 1  (f B ) of (an output circuit  121 A of) the microphone  111 A in the frequency band f B  as viewed from the signal processing circuit  113  is computed, and an equivalent circuit (impedance Z 2  (f B )) for the input impedance Z 1  (f B ) is designed using an element (for example, an element such as a fixed resistor, a capacitor, or an inductor) not converting, into an electric signal, the voice band (frequency band f A ) corresponding to the target information. 
     The circuit network  100 - 2  including an adjustment element  131 A with the impedance Z 2  (f B ) designed as described above is disposed in proximity to the circuit network  100 - 1  including the microphone  111 A to allow the (adjustment element  131 A of the) circuit network  100 - 2  to detect the signal S B2  in the wireless communication (frequency band f B ) performed by the transmission source  200 , that is, noise (signal similar to the signal S B1 ) superimposed on a sound pickup signal (signal S A1 ) picked up by the microphone  111 A. 
     Accordingly, in the signal processing circuit  113 , the signal with the signal S C1  superimposed on the signal S A1  is input to the input circuit  141 - 1 , and the signal S C2  is input to the input circuit  141 - 2 , in a case where the circuit networks lie within the reachable range of radio wave from the transmission source  200 . Then, the signal processing circuit  113  can remove the signal S C1  superimposed on the signal S A1  obtained by the input circuit  141 - 1 , by using the signal S C2  obtained by the input circuit  141 - 2 . 
     For example, in a case where an external microphone is attached to a video camera to pick up an image, when the microphone approaches a transceiver built in the video camera, a radio wave from the transceiver causes noise to be superimposed on a sound pickup signal (voice signal) picked up by the microphone because a cable of the external microphone has a high degree of freedom in arrangement. Then, a high frequency component of the noise is attenuated due to the frequency characteristic of the microphone amplifier, but noise in an audible range remains and is consequently heard. 
     The present technique is employed in such a case. In a radio wave (frequency band f B ) from the transceiver of the video camera, the circuit network  100 - 2  including the adjustment element  131  with the impedance Z 2  (f B ) corresponding to the input impedance Z 1  (f B ) of the output circuit  121 A of the microphone  111 A is disposed in proximity to the circuit network  100 - 1  including the microphone  111 A (the wiring  112 - 2  is disposed parallel to the wiring  112 - 1 ), to enable detection of noise in the same amount as that of noise caused by the radio wave, allowing removal of the noise. 
     As described above, in a case where the external microphone is used for the video camera, the noise sound caused by the radio wave from the internal or external transceiver can be reduced with the degree of freedom of the cable ensured. Note that the noise in this case may be caused by, instead of the radio wave from the transceiver built in the video camera, a radio wave from, for example, (a transceiver of) external equipment such as another camera or a smartphone. 
     (Third Example of Configuration of Present Technique) 
       FIG. 6  is a diagram illustrating a third example of a configuration of the noise canceling system to which present technique is applied. 
     The noise canceling system  10  can be provided, as the device  111 , with a circuit (analog output circuit) outputting analog signals for voice, temperature, humidity, angle information, acceleration information, imaging information, and the like, for example.  FIG. 6  illustrates a configuration in a case where a music player  111 B is provided as the device  111 . 
     In  FIG. 6 , the input impedance Z 1  (f B ) of (an output circuit  121 B of) the music player  111 B in the frequency band f B  as viewed from the signal processing circuit  113  is computed, and an equivalent circuit (impedance Z 2  (f B )) for the input impedance Z 1  (f B ) is designed using, for example, an element such as a fixed resistor, a capacitor, or an inductor. 
     The circuit network  100 - 2  including an adjustment element  131 B with the impedance Z 2  (f B ) designed as described above is disposed in proximity to the circuit network  100 - 1  including the music player  111 B, to allow the (adjustment element  131 B of the) circuit network  100 - 2  to detect the signal S B2  in the wireless communication (frequency band f B ) performed by the transmission source  200 , that is, noise (signal similar to the signal S B1 ) superimposed on an audio signal (signal S A1 ) output from the music player  111 B. 
     Accordingly, in the signal processing circuit  113 , the signal with the signal S C1  superimposed on the signal S A1  is input to the input circuit  141 - 1 , and the signal S C2  is input to the input circuit  141 - 2 , in a case where the circuit networks lie within the reachable range of radio wave from the transmission source  200 . Then, the signal processing circuit  113  can remove the signal S C1  superimposed on the signal S A1  obtained by the input circuit  141 - 1 , by using the signal S C2  obtained by the input circuit  141 - 2 . 
     (Fourth Example of Configuration of Present Technique) 
       FIG. 7  is a diagram illustrating a fourth example of a configuration of the noise canceling system to which the present technique is applied. 
     The noise canceling system  10  is provided with a plurality of the devices  111 , and in a case where the circuit network  100  including the device  111  is present in plural numbers, only one of the circuit networks  100  including the adjustment element  131  can be provided depending on arrangement conditions.  FIG. 7  illustrates such a configuration that, in a case where the circuit network  100  including the device  111  is provided in plural numbers, only one of the circuit networks  100  including the adjustment element  131  is provided. 
     In  FIG. 7 , the input impedance Z 1  (f B ) of (an output circuit  121 - 1  of) a device  111 - 1  in the frequency band f B  as viewed from the signal processing circuit  113  is computed, and an equivalent circuit (impedance Z 2  (f B )) for the input impedance Z 1  (f B ) is designed using, for example, an element such as a fixed resistor, a capacitor, or an inductor. 
     The circuit network  100 - 2  including the adjustment element  131  with the impedance Z 2  (f B ) designed as described above is disposed in proximity to the circuit network  100 - 1  including the device  111 - 1  (arrow D 12  in the figure) to allow the (adjustment element  131  of the) circuit network  100 - 2  to detect noise superimposed on a signal (signal S A1 ) output from the device  111 - 1 . 
     Additionally, the circuit network  100 - 2  including the adjustment element  131  is disposed in proximity to a circuit network  100 - 3  including a device  111 - 3  (arrow D 23  in the figure), to allow the (adjustment element  131  of the) circuit network  100 - 2  to detect noise superimposed on a signal (signal S A3 ) output from the device  111 - 3 . 
     For example, in a case where the device  111 - 1  and the device  111 - 3  correspond to input sections of a microphone including two input lines corresponding to a left channel (Lch) and a right channel (Rch), only one of the circuit networks  100 , the circuit network  100 - 2  including the adjustment element  131 , may be provided, compared to the circuit network  100 - 1  including the device  111 - 1  for the left channel (Lch) and the circuit network  100 - 3  including the device  111 - 3  for the right channel (Rch). 
     Accordingly, in the signal processing circuit  113 , the signal with the signal S C1  superimposed on the signal S A1  is input to the input circuit  141 - 1 , and the signal S C2  is input to the input circuit  141 - 2 . Then, the signal processing circuit  113  can remove the signal S C1  superimposed on the signal S A1  obtained by the input circuit  141 - 1 , by using the signal S C2  obtained by the input circuit  141 - 2 . 
     Furthermore, in the signal processing circuit  113 , the signal with the signal S C3  superimposed on the signal S A3  is input to the input circuit  141 - 3 . Then, the signal processing circuit  113  can remove a signal S C3  superimposed on the signal S A3  obtained by the input circuit  141 - 3 , by using the signal S C2  obtained by the input circuit  141 - 2 . 
     Note that  FIG. 7  illustrates the configuration in which, compared to the circuit networks  100 - 1  and  100 - 3  respectively including the devices  111 - 1  and  111 - 3 , only one of the circuit networks  100 , the circuit network  100 - 2  including the adjustment element  131 , is provided, but the number of circuit networks  100  including the different devices  111  is not limited to two, and three or more circuit networks  100  may include the different devices  111 . In short, it is sufficient that the number of circuit networks  100  including the adjustment element  131  is smaller than the number of circuit networks  100  including the different devices  111 , and the number of circuit networks  100  is optional. 
     As described above, according to the present technique, the adjustment element  131  designed under the predetermined conditions for the circuit network  100  is provided to enable removal of only the signal (noise) induced by a radio wave when the signal (noise) induced by the radio wave is superimposed on an analog signal. As a result, the noise induced by the radio wave can be reliably removed. 
     In particular, IoT devices are assumed to generally deal with signals ranging from high-frequency radio signals to low-frequency analog signals. For example, a certain sensor is used to acquire information from the outside world (for example, voice), and the information is caused to be transmitted to the signal processing circuit in the IoT device, or in contrast, information (for example, voice) resulting from signal processing executed by the signal processing circuit in the IoT device is transmitted to the outside world to be output. 
     Here, analog signals generally have low noise immunity, and thus, noise induced by a radio wave is non-negligible for these signals. For example, in the IoT device, when analog signal information is transmitted, longer wiring (signal line) of the IoT device leads to more susceptibility to the noise caused by the radio wave. Meanwhile, the noise induced by the radio wave may be generated due to not only the wireless communication function of the IoT device itself, but also wireless communication performed by other surrounding equipment. 
     For such IoT devices as well, application of the present technique allows only the signal (noise) induced by a radio wave to be similarly removed when the signal (noise) induced by the radio wave is superimposed on an analog signal. 
     &lt;2. Modified Example&gt; 
     In the above-described case, the noise superimposed on the analog signal is removed. However, noise superimposed on a digital signal can similarly be removed. 
     For example, in a case where, in the circuit network  100 - 1  ( FIG. 4 ), an AD conversion is used to convert an analog signal into a digital signal, the adjustment element  131  may be used to make the input impedance Z 1  in an analog circuit equivalent to the impedance Z 2 . Additionally, for example, in a case where, in the device  111 , an AD conversion is used to convert an analog signal into a digital signal, noise induced on the digital signal (frequency band f A ) by a radio wave can be removed depending on the conditions. 
     Additionally, in the above description, the adjustment element  131  includes a fixed resistor, a capacitor, an inductor, or the like. However, the adjustment element  131  may be configured using a variable element (for example, a variable resistor, capacitor, or the like). With the configuration that the adjustment element  131  includes a variable element, for example, the user can set (adjust) the level of noise detection to an optional level. 
     Note that, in the embodiment of the present technique, the wireless communication (frequency band f B ) performed by the transmission source  200  includes wireless communication in accordance with any of various communication schemes, for example, wireless LAN (Local Area Network) (Wi-Fi (registered trademark)), Bluetooth (registered trademark), mobile communication (for example, LTE-Advanced, 5G (5th Generation), Wideband CDMA (Code Division Multiple Access), GSM (registered trademark) (Global System for Mobile Communications), EDGE (Enhanced Data GSM (registered trademark) Environment), and the like), NFC (Near Field Communication), RFID (Radio Frequency Identifier), and the like. 
     Furthermore, as is the case with wireless LAN and the like as described above, an RF noise signal is assumed to be induced to the input signal by, for example, radio waves utilized for television broadcasting such as UHF (Ultra High Frequency) and VHF (Very High Frequency), FM broadcasting, and the like, and by microwaves from a microwave oven, and the present technique is effective for those radio waves. 
     Additionally, the configuration for removing noise (RF noise signal) superimposed on an analog signal or a digital signal to be transmitted via the wiring  112 - 1  has been described above. In this regard, the analog signal or the digital signal is assumed to be a signal corresponding to voice, video content, or various kinds of other data, for example. 
     &lt;3. Configuration of Computer&gt; 
     The series of steps of processing described above (for example, the noise removal processing to be executed by the signal processing circuit  113 ) can be executed by hardware or by software. In a case where the series of steps of processing is executed by software, a program included in the software is installed in a computer of an apparatus.  FIG. 8  is a block diagram illustrating a configuration example of hardware of a computer executing the above-described series of steps of processing by a program. 
     In a computer  1000 , a CPU (Central Processing Unit)  1001 , a ROM (Read Only Memory)  1002 , and a RAM (Random Access Memory)  1003  are connected together by a bus  1004 . An input/output interface  1005  is further connected to the bus  1004 . An input section  1006 , an output section  1007 , a recording section  1008 , a communication section  1009 , and a drive  1010  are connected to the input/output interface  1005 . 
     The input section  1006  includes a microphone, a keyboard, a mouse, and the like. The output section  1007  includes a speaker, a display, and the like. The recording section  1008  includes a hard disk, a nonvolatile memory, and the like. The communication section  1009  includes a network interface and the like. The drive  1010  drives a removable recording medium  1011  such as a magnetic disk, an optical disc, a magneto-optical disc, or a semiconductor memory. 
     In the computer  1000  configured as described above, the CPU  1001  loads a program recorded in the ROM  1002  or the recording section  1008  into the RAM  1003  through the input/output interface  1005  and the bus  1004  and executes the program to execute the above-described series of steps of processing. 
     The program to be executed by the computer  1000  (CPU  1001 ) can be provided by being recorded in, for example, a removable recording medium  1011  used as a package medium or the like. Additionally, the program can be provided via a wired or wireless transmission medium such as a local area network, the Internet, and digital satellite broadcasting. 
     In the computer  1000 , the program can be installed in the recording section  1008  through the input/output interface  1005  by loading the removable recording medium  1011  to the drive  1010 . Additionally, the program can be received by the communication section  1009  via a wired or wireless transmission medium and installed in the recording section  1008 . In addition, the program can be pre-installed in the ROM  1002  or the recording section  1008 . 
     Note that the processing executed by the computer in accordance with the program also includes steps of processing executed in parallel or individually (for example, parallel processing or object-based processing). Additionally, the program may be processed by one computer (processor) or processed a plurality of computers in a distributed manner. 
     &lt;4. Applied Example&gt; 
     The technique according to the present disclosure can be applied to various products. For example, the technique according to the present disclosure may be applied to an endoscopic surgery system. 
       FIG. 9  is a view depicting an example of a schematic configuration of an endoscopic surgery system  5000  to which the technology according to an embodiment of the present disclosure can be applied. In  FIG. 9 , a state is illustrated in which a surgeon (medical doctor)  5067  is using the endoscopic surgery system  5000  to perform surgery for a patient  5071  on a patient bed  5069 . As depicted, the endoscopic surgery system  5000  includes an endoscope  5001 , other surgical tools  5017 , a supporting arm apparatus  5027  which supports the endoscope  5001  thereon, and a cart  5037  on which various apparatus for endoscopic surgery are mounted. 
     In endoscopic surgery, in place of incision of the abdominal wall to perform laparotomy, a plurality of tubular aperture devices called trocars  5025   a  to  5025   d  are used to puncture the abdominal wall. Then, a lens barrel  5003  of the endoscope  5001  and the other surgical tools  5017  are inserted into body cavity of the patient  5071  through the trocars  5025   a  to  5025   d.  In the example depicted, as the other surgical tools  5017 , a pneumoperitoneum tube  5019 , an energy device  5021  and forceps  5023  are inserted into body cavity of the patient  5071 . Further, the energy device  5021  is a treatment tool for performing incision and peeling of a tissue, sealing of a blood vessel or the like by high frequency current or ultrasonic vibration. However, the surgical tools  5017  depicted are mere examples at all, and as the surgical tools  5017 , various surgical tools which are generally used in endoscopic surgery such as, for example, tweezers or a retractor may be used. 
     An image of a surgical region in a body cavity of the patient  5071  imaged by the endoscope  5001  is displayed on a display apparatus  5041 . The surgeon  5067  would use the energy device  5021  or the forceps  5023  while watching the image of the surgical region displayed on the display apparatus  5041  on the real time basis to perform such treatment as, for example, resection of an affected area. It is to be noted that, though not depicted, the pneumoperitoneum tube  5019 , the energy device  5021  and the forceps  5023  are supported by the surgeon  5067 , an assistant or the like during surgery. 
     (Supporting Arm Apparatus) 
     The supporting arm apparatus  5027  includes an arm unit  5031  extending from a base unit  5029 . In the example depicted, the arm unit  5031  includes joint portions  5033   a,    5033   b  and  5033   c  and links  5035   a  and  5035   b  and is driven under the control of an arm controlling apparatus  5045 . The endoscope  5001  is supported by the arm unit  5031  such that the position and the posture of the endoscope  5001  are controlled. Consequently, stable fixation in position of the endoscope  5001  can be implemented. 
     (Endoscope) 
     The endoscope  5001  includes the lens barrel  5003  which has a region of a predetermined length from a distal end thereof to be inserted into a body cavity of the patient  5071 , and a camera head  5005  connected to a proximal end of the lens barrel  5003 . In the example depicted, the endoscope  5001  is depicted as a rigid endoscope having the lens barrel  5003  of the hard type. However, the endoscope  5001  may otherwise be configured as a flexible endoscope having the lens barrel  5003  of the flexible type. 
     The lens barrel  5003  has, at a distal end thereof, an opening in which an objective lens is fitted. A light source apparatus  5043  is connected to the endoscope  5001  such that light generated by the light source apparatus  5043  is introduced to a distal end of the lens barrel by a light guide extending in the inside of the lens barrel  5003  and is irradiated toward an observation target in a body cavity of the patient  5071  through the objective lens. It is to be noted that the endoscope  5001  may be a forward-viewing endoscope or may be an oblique-viewing endoscope or a side-viewing endoscope. 
     An optical system and an image pickup element are provided in the inside of the camera head  5005  such that reflected light (observation light) from an observation target is condensed on the image pickup element by the optical system. The observation light is photo-electrically converted by the image pickup element to generate an electric signal corresponding to the observation light, namely, an image signal corresponding to an observation image. The image signal is transmitted as RAW data to a CCU  5039 . It is to be noted that the camera head  5005  has a function incorporated therein for suitably driving the optical system of the camera head  5005  to adjust the magnification and the focal distance. 
     It is to be noted that, in order to establish compatibility with, for example, a stereoscopic vision (three dimensional (3D) display), a plurality of image pickup elements may be provided on the camera head  5005 . In this case, a plurality of relay optical systems are provided in the inside of the lens barrel  5003  in order to guide observation light to each of the plurality of image pickup elements. 
     (Various Apparatus Incorporated in Cart) 
     The CCU  5039  includes a central processing unit (CPU), a graphics processing unit (GPU) or the like and integrally controls operation of the endoscope  5001  and the display apparatus  5041 . In particular, the CCU  5039  performs, for an image signal received from the camera head  5005 , various image processes for displaying an image based on the image signal such as, for example, a development process (demosaic process). The CCU  5039  provides the image signal for which the image processes have been performed to the display apparatus  5041 . Further, the CCU  5039  transmits a control signal to the camera head  5005  to control driving of the camera head  5005 . The control signal may include information relating to an image pickup condition such as a magnification or a focal distance. 
     The display apparatus  5041  displays an image based on an image signal for which the image processes have been performed by the CCU  5039  under the control of the CCU  5039 . If the endoscope  5001  is ready for imaging of a high resolution such as 4K (horizontal pixel number 3840×vertical pixel number 2160), 8K (horizontal pixel number 7680×vertical pixel number 4320) or the like and/or ready for 3D display, then a display apparatus by which corresponding display of the high resolution and/or 3D display are possible may be used as the display apparatus  5041 . Where the apparatus is ready for imaging of a high resolution such as 4K or 8K, if the display apparatus used as the display apparatus  5041  has a size of equal to or not less than 55 inches, then a more immersive experience can be obtained. Further, a plurality of display apparatus  5041  having different resolutions and/or different sizes may be provided in accordance with purposes. 
     The light source apparatus  5043  includes a light source such as, for example, a light emitting diode (LED) and supplies irradiation light for imaging of a surgical region to the endoscope  5001 . 
     The arm controlling apparatus  5045  includes a processor such as, for example, a CPU and operates in accordance with a predetermined program to control driving of the arm unit  5031  of the supporting arm apparatus  5027  in accordance with a predetermined controlling method. 
     An inputting apparatus  5047  is an input interface for the endoscopic surgery system  5000 . A user can perform inputting of various kinds of information or instruction inputting to the endoscopic surgery system  5000  through the inputting apparatus  5047 . For example, the user would input various kinds of information relating to surgery such as physical information of a patient, information regarding a surgical procedure of the surgery and so forth through the inputting apparatus  5047 . Further, the user would input, for example, an instruction to drive the arm unit  5031 , an instruction to change an image pickup condition (type of irradiation light, magnification, focal distance or the like) by the endoscope  5001 , an instruction to drive the energy device  5021  or the like through the inputting apparatus  5047 . 
     The type of the inputting apparatus  5047  is not limited and may be that of any one of various known inputting apparatus. As the inputting apparatus  5047 , for example, a mouse, a keyboard, a touch panel, a switch, a foot switch  5057  and/or a lever or the like may be applied. Where a touch panel is used as the inputting apparatus  5047 , it may be provided on the display face of the display apparatus  5041 . 
     Otherwise, the inputting apparatus  5047  is a device to be mounted on a user such as, for example, a glasses type wearable device or a head mounted display (HMD), and various kinds of inputting are performed in response to a gesture or a line of sight of the user detected by any of the devices mentioned. Further, the inputting apparatus  5047  includes a camera which can detect a motion of a user, and various kinds of inputting are performed in response to a gesture or a line of sight of a user detected from a video imaged by the camera. Further, the inputting apparatus  5047  includes a microphone which can collect the voice of a user, and various kinds of inputting are performed by voice collected by the microphone. By configuring the inputting apparatus  5047  such that various kinds of information can be inputted in a contactless fashion in this manner, especially a user who belongs to a clean area (for example, the surgeon  5067 ) can operate an apparatus belonging to an unclean area in a contactless fashion. Further, since the user can operate an apparatus without releasing a possessed surgical tool from its hand, the convenience to the user is improved. 
     A treatment tool controlling apparatus  5049  controls driving of the energy device  5021  for cautery or incision of a tissue, sealing of a blood vessel or the like. A pneumoperitoneum apparatus  5051  feeds gas into a body cavity of the patient  5071  through the pneumoperitoneum tube  5019  to inflate the body cavity in order to secure the field of view of the endoscope  5001  and secure the working space for the surgeon. A recorder  5053  is an apparatus capable of recording various kinds of information relating to surgery. A printer  5055  is an apparatus capable of printing various kinds of information relating to surgery in various forms such as a text, an image or a graph. 
     In the following, especially a characteristic configuration of the endoscopic surgery system  5000  is described in more detail. 
     (Supporting Arm Apparatus) 
     The supporting arm apparatus  5027  includes the base unit  5029  serving as a base, and the arm unit  5031  extending from the base unit  5029 . In the example depicted, the arm unit  5031  includes the plurality of joint portions  5033   a,    5033   b  and  5033   c  and the plurality of links  5035   a  and  5035   b  connected to each other by the joint portion  5033   b.  In  FIG. 9 , for simplified illustration, the configuration of the arm unit  5031  is depicted in a simplified form. Actually, the shape, number and arrangement of the joint portions  5033   a  to  5033   c  and the links  5035   a  and  5035   b  and the direction and so forth of axes of rotation of the joint portions  5033   a  to  5033   c  can be set suitably such that the arm unit  5031  has a desired degree of freedom. For example, the arm unit  5031  may preferably be configured such that it has a degree of freedom equal to or not less than 6 degrees of freedom. This makes it possible to move the endoscope  5001  freely within the movable range of the arm unit  5031 . Consequently, it becomes possible to insert the lens barrel  5003  of the endoscope  5001  from a desired direction into a body cavity of the patient  5071 . 
     An actuator is provided in each of the joint portions  5033   a  to  5033   c,  and the joint portions  5033   a  to  5033   c  are configured such that they are rotatable around predetermined axes of rotation thereof by driving of the respective actuators. The driving of the actuators is controlled by the arm controlling apparatus  5045  to control the rotational angle of each of the joint portions  5033   a  to  5033   c  thereby to control driving of the arm unit  5031 . Consequently, control of the position and the posture of the endoscope  5001  can be implemented. Thereupon, the arm controlling apparatus  5045  can control driving of the arm unit  5031  by various known controlling methods such as force control or position control. 
     For example, if the surgeon  5067  suitably performs operation inputting through the inputting apparatus  5047  (including the foot switch  5057 ), then driving of the arm unit  5031  may be controlled suitably by the arm controlling apparatus  5045  in response to the operation input to control the position and the posture of the endoscope  5001 . After the endoscope  5001  at the distal end of the arm unit  5031  is moved from an arbitrary position to a different arbitrary position by the control just described, the endoscope  5001  can be supported fixedly at the position after the movement. It is to be noted that the arm unit  5031  may be operated in a master-slave fashion. In this case, the arm unit  5031  may be remotely controlled by the user through the inputting apparatus  5047  which is placed at a place remote from the operating room. 
     Further, where force control is applied, the arm controlling apparatus  5045  may perform power-assisted control to drive the actuators of the joint portions  5033   a  to  5033   c  such that the arm unit  5031  may receive external force by the user and move smoothly following the external force. This makes it possible to move, when the user directly touches with and moves the arm unit  5031 , the arm unit  5031  with comparatively weak force. Accordingly, it becomes possible for the user to move the endoscope  5001  more intuitively by a simpler and easier operation, and the convenience to the user can be improved. 
     Here, generally in endoscopic surgery, the endoscope  5001  is supported by a medical doctor called scopist. In contrast, where the supporting arm apparatus  5027  is used, the position of the endoscope  5001  can be fixed more certainly without hands, and therefore, an image of a surgical region can be obtained stably and surgery can be performed smoothly. 
     It is to be noted that the arm controlling apparatus  5045  may not necessarily be provided on the cart  5037 . Further, the arm controlling apparatus  5045  may not necessarily be a single apparatus. For example, the arm controlling apparatus  5045  may be provided in each of the joint portions  5033   a  to  5033   c  of the arm unit  5031  of the supporting arm apparatus  5027  such that the plurality of arm controlling apparatus  5045  cooperate with each other to implement driving control of the arm unit  5031 . 
     (Light Source Apparatus) 
     The light source apparatus  5043  supplies irradiation light upon imaging of a surgical region to the endoscope  5001 . The light source apparatus  5043  includes a white light source which includes, for example, an LED, a laser light source or a combination of them. In this case, where a white light source includes a combination of red, green, and blue (RGB) laser light sources, since the output intensity and the output timing can be controlled with a high degree of accuracy for each color (each wavelength), adjustment of the white balance of a picked up image can be performed by the light source apparatus  5043 . Further, in this case, if laser beams from the respective RGB laser light sources are irradiated time-divisionally on an observation target and driving of the image pickup elements of the camera head  5005  is controlled in synchronism with the irradiation timings, then images individually corresponding to the R, G and B colors can be picked up time-divisionally. According to the method just described, a color image can be obtained even if a color filter is not provided for the image pickup element. 
     Further, driving of the light source apparatus  5043  may be controlled such that the intensity of light to be outputted is changed for each predetermined time. By controlling driving of the image pickup element of the camera head  5005  in synchronism with the timing of the change of the intensity of light to acquire images time-divisionally and synthesizing the images, an image of a high dynamic range free from underexposed blocked up shadows and overexposed highlights can be created. 
     Further, the light source apparatus  5043  may be configured to supply light of a predetermined wavelength band ready for special light observation. In special light observation, for example, by utilizing the wavelength dependency of absorption of light in a body tissue to irradiate light of a narrower wavelength band in comparison with irradiation light upon ordinary observation (namely, white light), narrow band light observation (narrow band imaging) of imaging a predetermined tissue such as a blood vessel of a superficial portion of the mucous membrane or the like in a high contrast is performed. Alternatively, in special light observation, fluorescent observation for obtaining an image from fluorescent light generated by irradiation of excitation light may be performed. In fluorescent observation, it is possible to perform observation of fluorescent light from a body tissue by irradiating excitation light on the body tissue (autofluorescence observation) or to obtain a fluorescent light image by locally injecting a reagent such as indocyanine green (ICG) into a body tissue and irradiating excitation light corresponding to a fluorescent light wavelength of the reagent upon the body tissue. The light source apparatus  5043  can be configured to supply such narrow-band light and/or excitation light suitable for special light observation as described above. 
     (Camera Head and CCU) 
     Functions of the camera head  5005  of the endoscope  5001  and the CCU  5039  are described in more detail with reference to  FIG. 10 .  FIG. 10  is a block diagram depicting an example of a functional configuration of the camera head  5005  and the CCU  5039  depicted in  FIG. 9 . 
     Referring to  FIG. 10 , the camera head  5005  has, as functions thereof, a lens unit  5007 , an image pickup unit  5009 , a driving unit  5011 , a communication unit  5013  and a camera head controlling unit  5015 . Further, the CCU  5039  has, as functions thereof, a communication unit  5059 , an image processing unit  5061  and a control unit  5063 . The camera head  5005  and the CCU  5039  are connected to be bidirectionally communicable to each other by a transmission cable  5065 . 
     First, a functional configuration of the camera head  5005  is described. The lens unit  5007  is an optical system provided at a connecting location of the camera head  5005  to the lens barrel  5003 . Observation light taken in from a distal end of the lens barrel  5003  is introduced into the camera head  5005  and enters the lens unit  5007 . The lens unit  5007  includes a combination of a plurality of lenses including a zoom lens and a focusing lens. The lens unit  5007  has optical properties adjusted such that the observation light is condensed on a light receiving face of the image pickup element of the image pickup unit  5009 . Further, the zoom lens and the focusing lens are configured such that the positions thereof on their optical axis are movable for adjustment of the magnification and the focal point of a picked up image. 
     The image pickup unit  5009  includes an image pickup element and disposed at a succeeding stage to the lens unit  5007 . Observation light having passed through the lens unit  5007  is condensed on the light receiving face of the image pickup element, and an image signal corresponding to the observation image is generated by photoelectric conversion of the image pickup element. The image signal generated by the image pickup unit  5009  is provided to the communication unit  5013 . 
     As the image pickup element which is included by the image pickup unit  5009 , an image sensor, for example, of the complementary metal oxide semiconductor (CMOS) type is used which has a Bayer array and is capable of picking up an image in color. It is to be noted that, as the image pickup element, an image pickup element may be used which is ready, for example, for imaging of an image of a high resolution equal to or not less than 4K. If an image of a surgical region is obtained in a high resolution, then the surgeon  5067  can comprehend a state of the surgical region in enhanced details and can proceed with the surgery more smoothly. 
     Further, the image pickup element which is included by the image pickup unit  5009  includes such that it has a pair of image pickup elements for acquiring image signals for the right eye and the left eye compatible with 3D display. Where 3D display is applied, the surgeon  5067  can comprehend the depth of a living body tissue in the surgical region more accurately. It is to be noted that, if the image pickup unit  5009  is configured as that of the multi-plate type, then a plurality of systems of lens units  5007  are provided corresponding to the individual image pickup elements of the image pickup unit  5009 . 
     The image pickup unit  5009  may not necessarily be provided on the camera head  5005 . For example, the image pickup unit  5009  may be provided just behind the objective lens in the inside of the lens barrel  5003 . 
     The driving unit  5011  includes an actuator and moves the zoom lens and the focusing lens of the lens unit  5007  by a predetermined distance along the optical axis under the control of the camera head controlling unit  5015 . Consequently, the magnification and the focal point of a picked up image by the image pickup unit  5009  can be adjusted suitably. 
     The communication unit  5013  includes a communication apparatus for transmitting and receiving various kinds of information to and from the CCU  5039 . The communication unit  5013  transmits an image signal acquired from the image pickup unit  5009  as RAW data to the CCU  5039  through the transmission cable  5065 . Thereupon, in order to display a picked up image of a surgical region in low latency, preferably the image signal is transmitted by optical communication. This is because, upon surgery, the surgeon  5067  performs surgery while observing the state of an affected area through a picked up image, it is demanded for a moving image of the surgical region to be displayed on the real time basis as far as possible in order to achieve surgery with a higher degree of safety and certainty. Where optical communication is applied, a photoelectric conversion module for converting an electric signal into an optical signal is provided in the communication unit  5013 . After the image signal is converted into an optical signal by the photoelectric conversion module, it is transmitted to the CCU  5039  through the transmission cable  5065 . 
     Further, the communication unit  5013  receives a control signal for controlling driving of the camera head  5005  from the CCU  5039 . The control signal includes information relating to image pickup conditions such as, for example, information that a frame rate of a picked up image is designated, information that an exposure value upon image picking up is designated and/or information that a magnification and a focal point of a picked up image are designated. The communication unit  5013  provides the received control signal to the camera head controlling unit  5015 . It is to be noted that also the control signal from the CCU  5039  may be transmitted by optical communication. In this case, a photoelectric conversion module for converting an optical signal into an electric signal is provided in the communication unit  5013 . After the control signal is converted into an electric signal by the photoelectric conversion module, it is provided to the camera head controlling unit  5015 . 
     It is to be noted that the image pickup conditions such as the frame rate, exposure value, magnification or focal point are set automatically by the control unit  5063  of the CCU  5039  on the basis of an acquired image signal. In other words, an auto exposure (AE) function, an auto focus (AF) function and an auto white balance (AWB) function are incorporated in the endoscope  5001 . 
     The camera head controlling unit  5015  controls driving of the camera head  5005  on the basis of a control signal from the CCU  5039  received through the communication unit  5013 . For example, the camera head controlling unit  5015  controls driving of the image pickup element of the image pickup unit  5009  on the basis of information that a frame rate of a picked up image is designated and/or information that an exposure value upon image picking up is designated. Further, for example, the camera head controlling unit  5015  controls the driving unit  5011  to suitably move the zoom lens and the focus lens of the lens unit  5007  on the basis of information that a magnification and a focal point of a picked up image are designated. The camera head controlling unit  5015  may further include a function for storing information for identifying the lens barrel  5003  and/or the camera head  5005 . 
     It is to be noted that, by disposing the components such as the lens unit  5007  and the image pickup unit  5009  in a sealed structure having high airtightness and waterproof, the camera head  5005  can be provided with resistance to an autoclave sterilization process. 
     Now, a functional configuration of the CCU  5039  is described. The communication unit  5059  includes a communication apparatus for transmitting and receiving various kinds of information to and from the camera head  5005 . The communication unit  5059  receives an image signal transmitted thereto from the camera head  5005  through the transmission cable  5065 . Thereupon, the image signal may be transmitted preferably by optical communication as described above. In this case, for the compatibility with optical communication, the communication unit  5059  includes a photoelectric conversion module for converting an optical signal into an electric signal. The communication unit  5059  provides the image signal after conversion into an electric signal to the image processing unit  5061 . 
     Further, the communication unit  5059  transmits, to the camera head  5005 , a control signal for controlling driving of the camera head  5005 . The control signal may also be transmitted by optical communication. 
     The image processing unit  5061  performs various image processes for an image signal in the form of RAW data transmitted thereto from the camera head  5005 . The image processes include various known signal processes such as, for example, a development process, an image quality improving process (a bandwidth enhancement process, a super-resolution process, a noise reduction (NR) process and/or an image stabilization process) and/or an enlargement process (electronic zooming process). Further, the image processing unit  5061  performs a detection process for an image signal in order to perform AE, AF and AWB. 
     The image processing unit  5061  includes a processor such as a CPU or a GPU, and when the processor operates in accordance with a predetermined program, the image processes and the detection process described above can be performed. It is to be noted that, where the image processing unit  5061  includes a plurality of GPUs, the image processing unit  5061  suitably divides information relating to an image signal such that image processes are performed in parallel by the plurality of GPUs. 
     The control unit  5063  performs various kinds of control relating to image picking up of a surgical region by the endoscope  5001  and display of the picked up image. For example, the control unit  5063  generates a control signal for controlling driving of the camera head  5005 . Thereupon, if image pickup conditions are inputted by the user, then the control unit  5063  generates a control signal on the basis of the input by the user. 
     Alternatively, where the endoscope  5001  has an AE function, an AF function and an AWB function incorporated therein, the control unit  5063  suitably calculates an optimum exposure value, focal distance and white balance in response to a result of a detection process by the image processing unit  5061  and generates a control signal. 
     Further, the control unit  5063  controls the display apparatus  5041  to display an image of a surgical region on the basis of an image signal for which image processes have been performed by the image processing unit  5061 . Thereupon, the control unit  5063  recognizes various objects in the surgical region image using various image recognition technologies. For example, the control unit  5063  can recognize a surgical tool such as forceps, a particular living body region, bleeding, mist when the energy device  5021  is used and so forth by detecting the shape, color and so forth of edges of the objects included in the surgical region image. The control unit  5063  causes, when it controls the display unit  5041  to display a surgical region image, various kinds of surgery supporting information to be displayed in an overlapping manner with an image of the surgical region using a result of the recognition. Where surgery supporting information is displayed in an overlapping manner and presented to the surgeon  5067 , the surgeon  5067  can proceed with the surgery more safety and certainty. 
     The transmission cable  5065  which connects the camera head  5005  and the CCU  5039  to each other is an electric signal cable ready for communication of an electric signal, an optical fiber ready for optical communication or a composite cable ready for both of electrical and optical communication. 
     Here, while, in the example depicted, communication is performed by wired communication using the transmission cable  5065 , the communication between the camera head  5005  and the CCU  5039  may be performed otherwise by wireless communication. Where the communication between the camera head  5005  and the CCU  5039  is performed by wireless communication, there is no necessity to lay the transmission cable  5065  in the operating room. Therefore, such a situation that movement of medical staff in the operating room is disturbed by the transmission cable  5065  can be eliminated. 
     An example of the endoscopic surgery system  5000  to which the technology according to an embodiment of the present disclosure can be applied has been described above. It is to be noted here that, although the endoscopic surgery system  5000  has been described as an example, the system to which the technology according to an embodiment of the present disclosure can be applied is not limited to the example. For example, the technology according to an embodiment of the present disclosure may be applied to a flexible endoscopic system for inspection or a microscopic surgery system. 
     The technique according to the present disclosure may suitably be applied to the portion of the transmission cable  5065  connecting the camera head  5005  and the CCU  5039  among the configurations describe above. Specifically, for example, it can be considered that the camera head  5005  corresponds to the cable apparatus  11 , that the CCU  5039  corresponds to the noise canceling apparatus  12 , and that the transmission cable  5065  corresponds to the cable including the wiring  112 - 1  and the wiring  112 - 2 . Additionally, in the camera head  5005 , the image pickup unit  5009  or the like corresponds to the device  111 , and in addition to the configuration illustrated in  FIG. 10 , the adjustment element  131  connected to the wiring  112 - 2  is further provided. In other words, in the endoscopic surgery system  5000 , also when an analog video signal is transmitted through the transmission cable  5065 , noise (RF noise signal) can be removed in a similar method to the above-described method for voice signals (sound pickup signals). 
     As described above, by applying the technique according to the present disclosure to the portion of the transmission cable  5065  connecting the camera head  5005  and the CCU  5039 , for example, noise caused by a radio wave from an external transceiver can be reduced, allowing clearer images of the surgical region to be obtained. Thus, the surgery can be executed more safely and reliably. 
     Note that the embodiment of the present technique is not limited to the above-described embodiment and that various changes may be made without departing from the spirits of the present technique. 
     Additionally, the present technique can have the following configuration. 
     (1) 
     A cable apparatus including: 
     wiring for input which is electrically connected to a device and through which an input signal and an RF noise signal induced are transmitted, and 
     wiring for noise detection which is electrically connected to an adjustment element enabled to be adjusted to an impedance corresponding to an input impedance of an output circuit of the device and in which the RF noise signal is induced. 
     (2) 
     The cable apparatus according to (1) described above, in which 
     a first signal in a first frequency band output from the device and a second signal in a second frequency band induced by a radio wave are transmitted together to the wiring for input, and 
     the first signal in the first frequency band is not transmitted to the wiring for noise detection, and the second signal in the second frequency band induced by the radio wave is transmitted to the wiring for noise detection. 
     (3) 
     The cable apparatus according to (2) described above, in which 
     the first signal and the second signal are transmitted to the wiring for input in a case where the wiring for input is located within a reachable range of the radio wave from a transmission source for the radio wave, and 
     the first signal is not transmitted to the wiring for noise detection and the second signal is transmitted to the wiring for noise detection in a case where the wiring for noise detection is located within the reachable range of the radio wave. 
     (4) 
     The cable apparatus according to (2) or (3) described above, in which 
     the adjustment element is configured to be adjusted to the impedance such that a first circuit network including the device and the wiring for input and a second circuit network including the adjustment element and the wiring for noise detection have, in the second frequency band, an identical frequency characteristic or corresponding frequency characteristics. 
     (5) 
     The cable apparatus according to (2) or (3) described above, in which 
     in the second frequency band, a first period during which the radio wave is transmitted and a second period during which the radio wave is not transmitted are repeatedly present in a time domain, 
     a third frequency band of a third signal resulting from repetition of the first period and the second period includes a frequency band lower than the second frequency band and is included in the first frequency band, 
     a signal from the wiring for input includes a signal with the third signal superimposed on the first signal, and 
     a signal from the wiring for noise detection includes the third signal. 
     (6) 
     The cable apparatus according to any one of (1) to (5) described above, in which 
     the wiring for input and the wiring for noise detection are disposed in proximity to each other. 
     (7) 
     The cable apparatus according to (6) described above, in which 
     the wiring for input and the wiring for noise detection are disposed parallel to each other. 
     (8) 
     The cable apparatus according to (6) described above, in which 
     the wiring for input and the wiring for noise detection are combined into one cable. 
     (9) 
     The cable apparatus according to any one of (1) to (8) described above, in which 
     the wiring for input and the wiring for noise detection have a substantially identical length and substantially identical characteristics. (10) 
     The cable apparatus according to any one of (1) to (9) described above, in which 
     the input signal and the RF noise signal include analog signals. 
     (11) 
     The cable apparatus according to any one of (1) to (10) described above, in which 
     the input signal includes a voice signal. 
     (12) 
     The cable apparatus according to any one of (1) to (11) described above, in which 
     the device includes a sensor or an output apparatus which outputs an analog signal. 
     (13) 
     The cable apparatus according to any one of (1) to (12) described above, in which 
     the device includes a microphone. 
     (14) 
     The cable apparatus according to any one of (1) to (13) described above, in which 
     the adjustment element includes at least one of a resistor, a capacitor, or an inductor. 
     (15) 
     The cable apparatus according to (4) described above, in which 
     in a case where each of a plurality of the first circuit networks is provided with a different device, the single second circuit network is provided for the plurality of the first circuit networks. 
     (16) 
     The cable apparatus according to any one of (1) to (15) described above, further including: 
     the device; and 
     the adjustment element. 
     (17) 
     A noise canceling apparatus including: 
     a signal processing section configured to remove an RF noise signal to an input signal transmitted through wiring for input electrically connected to a device, using an RF noise signal induced in wiring for noise detection electrically connected to an adjustment element enabled to be adjusted to an impedance corresponding to an input impedance of an output circuit of the device. 
     (18) 
     The noise canceling apparatus according to (17) described above, in which 
     a first signal in a first frequency band output from the device and a second signal in a second frequency band induced by a radio wave are transmitted together to the wiring for input, and 
     the first signal in the first frequency band is not transmitted to the wiring for noise detection, and the second signal in the second frequency band induced by the radio wave is transmitted to the wiring for noise detection. 
     (19) 
     The noise canceling apparatus according to (18) described above, in which 
     the first signal and the second signal are transmitted to the wiring for input in a case where the wiring for input is located within a reachable range of the radio wave from a transmission source for the radio wave, and 
     the first signal is not transmitted to the wiring for noise detection and the second signal is transmitted to the wiring for noise detection in a case where the wiring for noise detection is located within the reachable range of the radio wave. 
     (20) 
     The noise canceling apparatus according to (18) or (19) described above, in which 
     the adjustment element is configured to be adjusted to the impedance such that a first circuit network including the device and the wiring for input and a second circuit network including the adjustment element and the wiring for noise detection have, in the second frequency band, an identical frequency characteristic or corresponding frequency characteristics 
     (21) 
     The noise canceling apparatus according to (18) or (19) described above, in which 
     in the second frequency band, a first period during which the radio wave is transmitted and a second period during which the radio wave is not transmitted are repeatedly present in a time domain, 
     a third frequency band of a third signal resulting from repetition of the first period and the second period includes a frequency band lower than the second frequency band and is included in the first frequency band, 
     a signal from the wiring for input includes a signal with the third signal superimposed on the first signal, 
     a signal from the wiring for noise detection includes the third signal, and 
     the signal processing section uses the third signal from the wiring for noise detection to remove the third signal superimposed on the first signal from the wiring for input. 
     (22) 
     The noise canceling apparatus according to any one of (17) to (21) described above, in which 
     the wiring for input and the wiring for noise detection are disposed in proximity to each other. 
     (23) 
     The noise canceling apparatus according to (22) described above, in which 
     the wiring for input and the wiring for noise detection are disposed parallel to each other. 
     (24) 
     The noise canceling apparatus according to (22) described above, in which 
     the wiring for input and the wiring for noise detection are combined into one cable. 
     (25) 
     The noise canceling apparatus according to any one of (17) to (24) described above, in which 
     the wiring for input and the wiring for noise detection have a substantially identical length and substantially identical characteristics. 
     (26) 
     The noise canceling apparatus according to any one of (17) to (25) described above, in which 
     the input signal and the RF noise signal include analog signals. 
     (27) 
     The noise canceling apparatus according to any one of (17) to (26) described above, in which 
     the input signal includes a voice signal. 
     (28) 
     The noise canceling apparatus according to any one of (17) to (27) described above, in which 
     the device includes a sensor or an output apparatus which outputs an analog signal. 
     (29) 
     The noise canceling apparatus according to any one of (17) to (28) described above, in which 
     the device includes a microphone. (30) 
     The noise canceling apparatus according to any one of (17) to (29) described above, in which 
     the adjustment element includes at least one of a resistor, a capacitor, or an inductor. 
     (31) 
     The noise canceling apparatus according to (20) described above, in which 
     in a case where each of a plurality of the first circuit networks is provided with a different device, the single second circuit network is provided for the plurality of the first circuit networks. 
     (32) 
     The noise canceling apparatus according to any one of (17) to (31) described above, further including: 
     the device; 
     the wiring for input; 
     the adjustment element; and 
     the wiring for noise detection. 
     (33) 
     A noise canceling method including: 
     by a noise canceling apparatus, 
     removing an RF noise signal to an input signal transmitted through wiring for input electrically connected to a device, using an RF noise signal induced in wiring for noise detection electrically connected to an adjustment element enabled to be adjusted to an impedance corresponding to an input impedance of an output circuit of the device. 
     REFERENCE SIGNS LIST 
       10  Noise canceling system,  11  Cable apparatus,  12  Noise canceling apparatus,  100 - 1 ,  100 - 2 ,  100 - 3  Circuit network,  111 ,  111 - 1 ,  111 - 3  Device,  111 A Microphone,  111 B Music player,  112 - 1 ,  112 - 2  Wiring,  113  Signal processing circuit,  121 ,  121 - 1 ,  121 - 3  Output circuit,  131 ,  131 A,  131 B Adjustment element,  141 - 1 ,  141 - 2 ,  141 - 3  Input circuit,  151 - 1 ,  151 - 2 ,  151 - 3  Signal line,  152 - 1 ,  152 - 2 ,  152 - 3  Ground line,  200  Transmission source,  1000  Computer,  1001  CPU