JP3822554B2

JP3822554B2 - Transceiver

Info

Publication number: JP3822554B2
Application number: JP2002321411A
Authority: JP
Inventors: 直志美濃谷; 愛一郎佐々木; 満品川
Original assignee: Nippon Telegraph and Telephone Corp
Current assignee: Nippon Telegraph and Telephone Corp
Priority date: 2002-11-05
Filing date: 2002-11-05
Publication date: 2006-09-20
Anticipated expiration: 2022-11-05
Also published as: JP2004158985A

Description

【０００１】
【発明の属する技術分野】
本発明は、電界を伝達する電界伝達媒体に誘起する電界を用いて情報の送受信を行うトランシーバに関し、より具体的には、人間の身体に装着可能なウェアラブルコンピュータを用いたデータ通信において使用されるトランシーバに関する。
【０００２】
【従来の技術】
携帯端末の小型化および高性能化により、生体に装着可能なウェアラブルコンピュータが注目されてきている。
【０００３】
従来、このようなウェアラブルコンピュータ間のデータ通信は、コンピュータにトランシーバを接続し、このトランシーバが誘起する電界を、電界伝達媒体である生体の内部を伝達することによってデータの送受信を行うことが提案されている（例えば、特許文献１参照）。
【０００４】
図７は、従来のトランシーバの構成を示すブロック図である。同図に示すトランシーバ３は、信号の入出力を行うＩ／Ｏ回路３０１を介してウェアラブルコンピュータ５に接続されるとともに、送受信電極３０５が絶縁体３０７を介して生体７に近接して設けられている。ウェアラブルコンピュータ５から送信される情報（データ）は、送信回路３０３から送受信電極３０５に供給され、送受信電極３０５から絶縁体３０７を介して生体７に電界を誘起し、この電界が生体７内部を伝達して生体７の他の部位に設けられたトランシーバ３や、生体７からの接触によって電気的に接続されるトランシーバ３にウェアラブルコンピュータ５から送信される情報を伝達する。
【０００５】
このようにトランシーバ３を介して伝達されてくる電界を別のトランシーバ３が受信する際には、絶縁体３０７を介して送受信電極３０５で受信した電界を電界検出光学部３０９で電気信号に変換し、信号処理回路３１１に供給する。信号処理回路３１１は、電界検出光学部３０９からの電気信号に対してフィルタリングや増幅等の信号処理を施す。信号処理の後、さらにデータの波形整形が波形整形回路３２５で行われ、これら一連の処理が施された信号がウェアラブルコンピュータ５の受信データとしてＩ／Ｏ回路３０１からウェアラブルコンピュータ５に送信される。
【０００６】
このようにウェアラブルコンピュータ５間のデータ通信に使用されるトランシーバ３は、送信すべき情報に基づく電界を電界伝達媒体である生体７に誘起し、この誘起した電界を用いて情報の送信を行う一方で、情報を受信する際には、生体７に誘起された電界を用いてトランシーバ３が信号を受信する。
【０００７】
図８は、ウェアラブルコンピュータ５を生体７の例である人間に装着して使用する場合の例を示す説明図である。同図に示すウェアラブルコンピュータ５ａ、５ｂ、および５ｃは、それぞれ対応して接続されるトランシーバ３ａ、３ｂ、および３ｃを介して人間の腕、肩、胴体などに装着されて互いにデータの送受信を行う。さらに、生体７の手足の先端が、外部機器である外部端末８０にケーブル９０を介して接続されるトランシーバ３’ａや３’ｂに接触する場合には、ウェアラブルコンピュータ５ａ、５ｂ、および５ｃと外部端末８０との間でデータの送受信を行うことができる。
【０００８】
【特許文献１】
特開２００１−３５２２９８号公報
【０００９】
【発明が解決しようとする課題】
しかしながら、上述したトランシーバを用いたウェアラブルコンピュータ同士が同時双方向通信を行う必要があるときには、送信側の送信回路が出力した信号が受信側の回路に混入するという問題があった。
【００１０】
本発明は上記に鑑みてなされたものであり、その目的は、同時双方向通信時に、受信側の回路に混入した送信回路の出力信号の影響を補償し、通信品質の向上を図ることが可能なトランシーバを提供することにある。
【００１１】
【課題を解決するための手段】
上記目的を達成するために、請求項１に記載の本発明は、送信すべき情報に基づく電界を電界伝達媒体に誘起し、この誘起した電界を用いて情報の送信を行う一方で、前記電界伝達媒体に誘起された受信すべき情報に基づく電界を受信することによって情報の受信を行うトランシーバであって、前記送信すべき情報に基づく電界を前記電界伝達媒体に誘起するための信号を送信する送信手段と、前記電界伝達媒体に誘起された受信すべき情報に基づく電界を少なくとも受信する受信手段と、前記受信手段は、前記受信すべき情報に基づく電界を検出し、この検出した電界を電気信号に変換する電界検出手段と、この電界検出手段から出力される信号と前記補償信号の差を求め、この差を増幅する差動増幅器と、を有し、前記電界伝達媒体を介した情報の送受信に際して、前記受信手段で受信する信号に混入する前記送信手段で送信した信号の影響を補償するための補償信号を発生する補償信号発生手段と、前記送信手段で送信する信号および前記受信手段で受信する信号に基づいて前記補償信号発生手段が有する特性の制御を行う制御信号を当該補償信号発生手段に出力する制御手段と、前記電界伝達媒体を介した情報の送受信を行うときには前記送信すべき情報を前記送信手段に直接送信可能な接続を行う一方で、前記補償信号発生手段の特性を予め制御するときには前記送信手段と前記制御手段とを接続する第１の接続手段と、前記情報の送受信を行うときには前記受信手段と入力される信号の波形を整形する波形整形回路とを接続する一方で、前記補償信号発生手段の特性を予め制御するときには前記受信手段と前記制御手段とを接続する第２の接続手段と、を備えることを要旨とする。
【００１２】
請求項１記載の本発明によれば、送信すべき情報に基づく電界を電界伝達媒体に誘起するための信号を送信する送信手段と、電界伝達媒体に誘起された受信すべき情報に基づく電界を少なくとも受信する受信手段と、電界伝達媒体を介した情報の送受信に際して、受信手段で受信する信号に混入した送信手段で送信した信号の影響を補償するための補償信号を発生する補償信号発生手段と、送信手段で送信する信号および受信手段で受信する信号に基づいて補償信号発生手段が有する特性を制御する制御信号を当該補償信号発生手段に出力する制御手段とを備えたトランシーバを提供することにより、受信器に混入した送信器の出力信号を補償し、通信品質の向上を図ることができ、
前記受信手段は、前記受信すべき情報に基づく電界を検出し、この検出した電界を電気信号に変換する電界検出手段と、この電界検出手段から出力される信号と前記補償信号発生手段から受信する前記補償信号の差を求め、この差を増幅する差動増幅器とを有し、
前記電界伝達媒体を介した情報の送受信を行うときには前記送信すべき情報を前記送信手段に直接送信可能な接続を行う一方で、前記補償信号発生手段の特性を予め制御するときには前記送信手段と前記制御手段とを接続する第１の接続手段と、前記情報の送受信を行うときには前記受信手段と入力される信号の波形を整形する波形整形回路とを接続する一方で、前記補償信号発生手段の特性を予め制御するときには前記受信手段と前記制御手段とを接続する第２の接続手段とを備えたことを要旨とする。
【００１３】
請求項２記載の本発明は、送信すべき情報に基づく電界を電界伝達媒体に誘起し、この誘起した電界を用いて情報の送信を行う一方で、前記電界伝達媒体に誘起された受信すべき情報に基づく電界を受信することによって情報の受信を行うトランシーバであって、前記送信すべき情報に基づく電界を前記電界伝達媒体に誘起するための信号を送信する送信手段と、前記電界伝達媒体に誘起された受信すべき情報に基づく電界を少なくとも受信する受信手段と、前記受信手段は、所定のレーザ光を発生するレーザダイオードと、前記受信すべき情報に基づく電界および前記補償信号発生手段で発生した信号に基づいて誘起される電界によって前記レーザダイオードから入射されるレーザ光の偏光状態を変化させる電気光学素子と、この電気光学素子を通過することによって偏光状態が変化したレーザ光の偏光変化量を当該レーザ光の強度変化に変換する偏光検出光学系と、を有し、前記電界伝達媒体を介した情報の送受信に際して、前記受信手段で受信する信号に混入する前記送信手段で送信した信号の影響を補償するための補償信号を発生する補償信号発生手段と、前記送信手段で送信する信号および前記受信手段で受信する信号に基づいて前記補償信号発生手段が有する特性の制御を行う制御信号を当該補償信号発生手段に出力する制御手段とを備えることを要旨とする。
【００１４】
請求項３記載の本発明は、送信すべき情報に基づく電界を電界伝達媒体に誘起し、この誘起した電界を用いて情報の送信を行う一方で、前記電界伝達媒体に誘起された受信すべき情報に基づく電界を受信することによって情報の受信を行うトランシーバであって、前記送信すべき情報に基づく電界を前記電界伝達媒体に誘起するための信号を送信する送信手段と、前記電界伝達媒体に誘起された受信すべき情報に基づく電界を少なくとも受信する受信手段と、前記電界伝達媒体を介した情報の送受信に際して、前記受信手段で受信する信号に混入する前記送信手段で送信した信号の影響を補償するための補償信号を発生する補償信号発生手段と、前記送信手段で送信する信号および前記受信手段で受信する信号に基づいて前記補償信号発生手段が有する特性の制御を行う制御信号を当該補償信号発生手段に出力する制御手段と、前記制御手段は、前記補償信号発生手段が有する特性を予め制御するときに前記送信手段を介して前記補償信号発生手段に入力する交流信号を発振する発振器と、この発振器から発振される交流信号と前記受信手段からの出力信号との乗算を取り、この乗算によって得られる信号の高調波成分を除去して振幅を検出する振幅検出部と、この振幅検出部からの出力信号を積分した結果に基づいて前記制御信号を発生する積分器と、前記補償信号発生手段の特性を一定に保つために当該補償信号発生手段に一定の電圧を印加可能な固定電圧源と、を有し、前記情報の送受信を行うときには前記積分器と前記固定電圧源とを接続する一方で、前記補償信号発生手段の特性を予め制御するときには前記振幅検出部と前記積分器とを接続する第３の接続手段と、を備えたことを特徴とするトランシーバ。
【００１６】
なお、ここで「補償信号発生手段の特性を予め制御するとき」とは、情報の送受信、すなわち異なるトランシーバ間の同時双方向通信を行う前の時点のみならず、同時双方向受信時に不具合が生じたときに通信を中止して制御を行う場合をも含むものとする。
【００１７】
請求項４記載の本発明は、請求項１乃至３のいずれか一項において、前記補償信号発生手段は増幅器から成り、この増幅器が有する特性としての利得を前記制御手段が制御することを要旨とする。
【００２０】
【発明の実施の形態】
次に、図面を参照して本発明の実施の形態を説明する。
【００２１】
（第１の実施形態）
本発明の第１の実施形態は、送信手段から送信されるデータを、生体に誘起した電界を通して伝達する信号と補償信号発生手段への信号とに分け、この両者の差分がゼロとなるように予め補償信号発生手段の特性を制御しておくことによって、トランシーバで受信するデータに送信データの信号が混入するのを防止するものである。
【００２２】
図１は、本発明の第１の実施形態に係るトランシーバの構成を示すブロック図である。同図に示すトランシーバ１は、ウェアラブルコンピュータ５から送信されるデータ（情報）を出力するとともに受信した信号を受け取ってウェアラブルコンピュータ５へ出力するＩ／Ｏ回路１０１、データを送信する送信手段としての送信回路１０３、電界伝達媒体である生体７に電界を誘起するために導電性部材からなる送受信電極１０５、生体７に電流が流れるのを防止するとともに送受信電極１０５による生体７の金属アレルギの危険性を除去するために送受信電極１０５と生体７間に配置される絶縁体１０７、通信時に受信手段で受信する信号の波形整形を行ってＩ／Ｏ回路１０１へ出力する波形整形回路１２５を少なくとも有する。ここで送受信電極を、送信用電極および受信用電極に分割して設けることも勿論可能である。その場合には、絶縁体もそれぞれの電極に対応して二つ設けられる。
【００２３】
トランシーバ１は、以上に加えて、生体７に誘起された電界を受信してこの電界を光学的に検出した後、電気信号に変換する電界検出光学部１０９、電界検出光学部１０９から出力される信号に対して低雑音増幅、雑音除去、および波形整形等の信号処理を施す信号処理回路１１１を有しており、これらが電界検出手段を構成している。
【００２４】
この電界検出手段のうち、電界検出光学部１０９は、レーザ光と電気光学素子を用いた電気光学的手法によって電界を検出するものであり、少なくともレーザ光源を構成するレーザダイオードおよびＬｉＮｂＯ₃やＬｉＴａＯ₃等の電気光学結晶（ＥＯ結晶：Electro Optic 結晶）からなる電気光学素子を有する（図示せず）。この電気光学素子として、例えば、レーザダイオードから発射されるレーザ光の進行方向に対して垂直な方向の電界成分のみに感度を有し、この電界強度によって光学特性、すなわち複屈折率が変化し、この複屈折率の変化によりレーザ光の偏光が変化するようなものを用いることができる。また、場合によっては電界によって電気光学素子の結晶が歪む逆圧電効果による偏光の変化も含まれる。
【００２５】
このような電気光学素子を通過して偏光が変化したレーザ光は、波長板を用いて偏光状態の調整を受けた後、偏光ビームスプリッタに入射することによりＰ波およびＳ波に分離され、光の強度変化に変換される。分離された各レーザ光は、コリメータ（集光レンズ）で集光されてから、光を電気信号に変換するためにそれぞれ設けられる二つのフォトダイオードに供給され、例えばその差を差動増幅することによって受信した電界に係る電気信号として出力される。
【００２６】
なお、以上説明した電界検出光学部１０９の構成および作用はあくまでも一例であり、本実施形態に係るトランシーバ１に適用される電界検出光学部１０９が必ずしもこのような構成を有する場合にのみ特有の効果を奏するわけではない。
【００２７】
本実施形態に係るトランシーバ１の特徴は、以上の構成に加えて、送信回路１０３から信号を受信し、この信号の影響を補償する補償信号を発生する補償信号発生手段として、その特性である利得の調整可能な可変利得増幅器１２１を有する点にある。
【００２８】
この可変利得増幅器１２１を設けることに伴って、トランシーバ１は以下のような構成をさらに有する。
【００２９】
可変利得増幅器１２１から出力される補償信号（送信回路１０３の影響を補償するための信号）と電界検出手段で出力される信号との差分を増幅する差動増幅器１１３は、電界検出手段とあわせて受信手段を構成する。
【００３０】
差動増幅器１１３から出力される信号は、可変利得増幅器１２１が有する特性である利得を調整するときには、そのための制御信号を発生する制御手段に出力される。制御手段は、所定周波数の交流信号を基準信号として発振する発振器１１５、この発振器１１５からの信号と差動増幅器１１３からの信号を乗算する乗算器およびこの乗算器の出力信号の高調波成分を除去するフィルタを備えた振幅検出部１１７、振幅検出部１１７の出力信号を積分して可変利得増幅器１２１に利得を制御する制御信号を出力する積分器１１９、通信時に可変利得増幅器１２１の利得を一定に保つための信号を発生する固定電圧源１２３から構成される。
【００３１】
このうち、発振器１１５から発振する交流信号の周波数は、１０ｋＨｚ（キロヘルツ）〜１００ＭＨｚ（メガヘルツ）程度の値が想定されるが、１０ＭＨｚ程度であればより好ましい。ここで、１ｋＨｚ＝１０³Ｈｚ、１ＭＨｚ＝１０⁶Ｈｚである。
【００３２】
トランシーバ１には、回路の接続を切り替える接続手段として３つのスイッチＳＷ１（第１の接続手段）、ＳＷ２（第２の接続手段）、およびＳＷ３（第３の接続手段）が設けられており、各スイッチの接続の切替は、Ｉ／Ｏ回路１０１に接続した制御回路１６１からの接続切替制御信号によって行われる。なお、図１等において、Ａの丸印で記載されている箇所同士は配線によって接続していることを示している。制御回路１６１から発せられるスイッチ切替のための切替制御信号は、ウェアラブルコンピュータ５からの操作によって発生するようにしてもよいし、トランシーバ１に切替制御信号入力手段を適宜設け、この切替制御信号入力手段を用いて発生するようにしてもよい。なお、接続切替手段としての各スイッチおよび制御回路の構成がここで説明したものに限られるわけでないことはいうまでもない。
【００３３】
本実施形態においては、異なるウェアラブルコンピュータ５同士が同時双方向通信を行うことを想定しているため、各ウェアラブルコンピュータ５に近接して設けられるトランシーバ１は、同時双方向通信時に送信回路１０３から出力される信号が同じトランシーバ１の受信側回路に混入する恐れがある。そこで、この影響を抑制するために、同時双方向通信を行う前に、送信回路１０３の信号の影響を補償するための制御を予め行っておくか、不具合が生じるたびに適宜行う。この制御は、可変利得増幅器１２１が有する利得を調整することによって行われる。以後、利得調整時と同時双方向通信時とに分けてトランシーバ１の作用を説明する。
【００３４】
＜利得調整時＞
最初に、図１に示す利得調整時の各スイッチの接続を説明する。スイッチＳＷ１では、三つの端子のうち、端子ａ２−ａ３間を接続して発振器１１５からの信号が送信回路１０３に達するようにする。スイッチＳＷ２では端子ｂ１と端子ｂ３を閉成して差動増幅器１１３の出力信号が振幅検出部１１７に出力されるようにする。スイッチＳＷ３では端子ｃ２と端子ｃ３を閉成して振幅検出部１１７からの信号が積分器１１９へ出力されるようにする。以上のようにスイッチの接続を制御することにより、振幅検出部１１７、積分器１１９、可変利得増幅器１２１は差動増幅器１１３への負帰還回路を構成する。
【００３５】
発振器１１５の信号は送信回路１０３に送られ、可変利得増幅器１２１を介して差動増幅器１１３に送られる信号と生体７、電界検出光学部１０９、および信号処理回路１１１を介して差動増幅器１１３に送られる信号とに分割される。この二つの信号は差動増幅器１１３において両者の差分が求められ、この差分を増幅した信号がスイッチＳＷ２を経て振幅検出部１１７に入力される。
【００３６】
発振器１１５から直接振幅検出部１１７に出力される信号（基準信号）と差動増幅器１１３から出力される信号は、振幅検出部１１７内の乗算器において両者の積が求められた後、この積の高調波成分を振幅検出部１１７内のフィルタで除去して出力される。振幅検出部１１７の出力信号は積分器１１９で積分され、可変利得増幅器１２１に対する制御信号を発生することによって可変利得増幅器１２１の利得の調整を行う。このときの利得は、差動増幅器１１３の出力がゼロになるように調整される。換言すると、このように利得を調整することにより、送信回路１０３から可変利得増幅器１２１を介して差動増幅器１１３に入力される信号を、送信回路１０３から生体７を介して受信側に混入する信号と同等にすることができる。
【００３７】
図６は、利得調整時の利得制御信号を発生するまでに各構成ユニットから出力される信号波形の例を示す説明図である。
【００３８】
このうち図６（ａ）は可変利得増幅器１２１の利得が小さい場合の信号波形の変化を示すものである。この場合、差動増幅器１１３の出力信号６１と発振器１１５からの基準信号６３は同位相になる。したがって、振幅検出部１１７内の乗算器で両者を乗算することによって得られる出力信号６５は正方向のみの変位を有する波形になる。この出力信号６５の高調波成分を振幅検出部１１７内のフィルタを用いて除去したものが信号６７である。信号６７は積分器１１９で積分された後、利得を増加させる制御信号６９が積分器１１９から可変利得増幅器１２１に出力され、この結果、差動増幅器１１３の出力信号がゼロとなる。
【００３９】
図６（ｂ）は、利得が大きい場合の信号波形の変化を示す説明図である。この場合には差動増幅器１１３の出力信号７１は基準信号７３と逆位相になる。したがって、振幅検出部１１７内の乗算器によって両者を乗算して得られる出力信号７５は負方向のみの変位を有し、この出力信号７５の高調波成分を前述したフィルタを用いて除去した信号７７を積分器１１９で積分した結果、差動増幅器１１３の出力がゼロとなるように利得を減少させる制御信号７９が積分器１１９から可変利得増幅器１２１に出力されることになる。
【００４０】
＜同時双方向通信時＞
まず、図２のブロック図を用いて同時双方向通信時の各スイッチの接続状態を説明する。スイッチＳＷ１では端子ａ１と端子ａ３を閉成してＩ／Ｏ回路１０１から出力されるウェアラブルコンピュータ５の送信データが送信回路１０３に達するようにする。スイッチＳＷ２は端子ｂ２−ｂ３間を接続して差動増幅器１１３からの出力信号が波形整形回路１２５およびＩ／Ｏ回路１０１を介してウェアラブルコンピュータ５に受信データとして届くようにする。スイッチＳＷ３では可変利得増幅器１２１の調整後の利得を一定に保つため、端子ｃ１と端子ｃ３を接続して固定電圧源１２３から信号（通常はゼロの信号）を可変利得増幅器１２１に印加する。
【００４１】
これにより、送信データの情報が可変利得増幅器１２１および差動増幅器１１３によって相殺されるため、同時双方向通信を行っても、送信データが受信データに混入するのを防止することが可能になる。
【００４２】
以上説明した本発明の第１の実施形態によれば、可変利得増幅器の利得を予め制御（調整）しておくことにより、同時双方向通信時にトランシーバで受信するデータに自ら送信する送信データの信号が混入するのを防止し、通信品質を向上させる効果を得ることができる。
【００４３】
本実施形態に係るトランシーバは、例えば災害時等において作業者同士が会話をしながら作業を行う環境で、酸素マスクや防毒マスク等に具備させることにより、作業の際の会話を円滑に行うことが可能になる。
【００４４】
（第２の実施形態）
本発明の第２の実施形態に係るトランシーバは、可変利得増幅器からの出力信号も電界検出手段に入力し、その出力信号に基づいた電界と生体７を介して伝達される電界を用いて利得の調整および同時双方向通信を行うものである。
【００４５】
図３および図４は、本発明の第２の実施形態に係るトランシーバの利得調整時および同時双方向通信時の接続状態をそれぞれ示すブロック図である。両図に示すトランシーバ２において、Ｉ／Ｏ回路２０１、送信回路２０３、送受信電極２０５、絶縁体２０７、信号処理回路２１１、発振器２１５、振幅検出部２１７、積分器２１９、固定電圧源２２３、波形整形回路２２５、および制御回路２６１は、上記第１の実施形態に係るトランシーバ１の対応部位（図１および図２を参照）と同様の機能を有している。したがって、これらの対応部位については下２桁の符号を図１と揃えて記載してある。
【００４６】
また、第１、第２、および第３の接続手段として、スイッチＳＷ１、ＳＷ２、およびＳＷ３がそれぞれ設けられている点についても第１の実施形態と同様であり、これらのスイッチの制御が制御回路２６１を介して行われることも勿論同じである（図３および図４におけるＡの丸印が回路の接続を示している点も同様）。
【００４７】
さらに、発振器２１５が発振する周波数の値や、送受信電極を送信用電極および受信用電極に分割して設けてもよい点等も上記第１の実施形態と同様である。
【００４８】
補償信号発生手段としての可変利得増幅器２２１では、送信回路２０３から送信される信号とは出力を反転した信号、すなわち位相が反転した信号を補償信号として出力する。この信号は第１の実施形態とは異なり、信号処理回路２１１とあわせて受信手段をなす電界検出光学部２０９に出力される。
【００４９】
図５は、電界検出光学部２０９の詳細な構成を示す説明図である。同図に示す電界検出光学部２０９は、レーザ光と電気光学結晶を用いた電気光学的手法により電界を検出するものであり、レーザ光源を構成するレーザダイオード（ＬＤ）２２７および上記第１の実施形態で説明したものと同様の電気光学結晶からなる電気光学素子２２９を有する。なお、電気光学素子２２９は、レーザダイオード２２７からのレーザ光の進行方向に対して直角方向の電界成分のみに対して感度を有し、この電界強度によって光学特性、すなわち複屈折率が変化することによってレーザ光の偏光状態が変化する。
【００５０】
電気光学素子２２９のレーザ光入射方向に平行な二つの側面（図上で左右方向に対向する両側面）のうち、一方の側面（図の右側）には二つの電極２３１および２３３が、他方の側面（図の左側）にはグランド電極２４３と接続された電極２４１が設けられている。電極２３１は可変利得増幅器２２１から出力される補償信号を受信し、この補償信号によって生じる電極２４１との電位差に応じた電界を電気光学素子２２９内部のレーザ光入射方向と直交する方向に誘起する。また、電極２３３は、生体７に誘起され、送受信電極２０５を介して受信する電界に基づいた信号を受信し、生体７から受信した電界をレーザ光入射方向と直交する方向に誘起する。可変利得増幅器２２１において出力される補償信号は位相を反転させた信号である。これは、前述した二つの電界による電気光学効果が相殺されるように可変利得増幅器２２１の利得を予め制御しておけば、送信回路２０３から送信される送信データが受信データに混入することを防止することができるためである。以下、そのための具体的な電界検出光学部２０９の構成についてさらに説明を加える。
【００５１】
レーザダイオード２２７から出力されるレーザ光は、コリメートレンズ２３７を介して平行光にされ、平行光となったレーザ光は第１波長板２３９で偏光状態が調整されて電気光学素子２２９に入射する。電気光学素子２２９に入射したレーザ光は、上述した二つの電界によって電気光学素子２２９の光学特性である複屈折率が変化することに伴って偏光状態が変化する。
【００５２】
このように偏光状態が変化したレーザ光は、第２波長板２４５で偏光状態が調整されて偏光ビームスプリッタ２４７に入射される。偏光ビームスプリッタ２４７では、第２波長板２４５から入射されたレーザ光をＰ波およびＳ波に分離して、光の強度変化に変換する。この偏光ビームスプリッタ２４７でＰ波成分およびＳ波成分に分離されたレーザ光は、コリメートレンズ２４９および２５１でそれぞれ集光された後、フォトダイオード２５３および２５５にそれぞれ供給されて電気信号に変換される。その後、二つの電気信号は差動増幅器２５７に入力されてその差分が求められ、増幅されて信号処理回路２１１へ出力される。
【００５３】
以上の構成を有するトランシーバ２の作用について、可変利得増幅器２２１の利得調整時と同時双方向通信時に分けて説明する。
【００５４】
＜利得調整時＞
まず、図３に示す利得調整時の各スイッチの接続状態を説明する。スイッチＳＷ１では、三つの端子のうち、端子ａ２−ａ３間を接続して発振器２１５からの信号が送信回路２０３に達するようにする。スイッチＳＷ２では端子ｂ１と端子ｂ３を閉成して信号処理回路２１１の出力信号が振幅検出部２１７に出力されるようにする。スイッチＳＷ３では端子ｃ２と端子ｃ３を閉成して振幅検出部２１７からの信号が積分器２１９へ出力されるようにする。以上のように各スイッチの接続を制御することにより、振幅検出部２１７、積分器２１９、可変利得増幅器２２１、および電気光学素子２２９が実質的に負帰還回路を構成する。
【００５５】
発振器２１５から発振される交流信号は送信回路２０３と振幅検出部２１７分けて基準信号として出力される。このうち送信回路２０３に出力された基準信号は、可変利得増幅器２２１を介して電界検出光学部２０９の電極２３１に達し、電気光学素子２２９に入射されるレーザ光の入射方向と直交する電界をその電気光学素子２２９内に誘起する。ここで、可変利得増幅器２２１では、送信回路２０３から到達する信号に対して出力を反転させた補償信号を電極２３１に出力する。このように出力を反転させることにより、生体７から受信する電界とあわせた電気光学効果によって偏光検出光学系２３５内の差動増幅器２５７の出力をゼロとするような利得の調整を行うことで送信データの混入を防止することができる。
【００５６】
差動増幅器２５７でその差が増幅された信号は、信号処理回路２１１へ送信されて低雑音増幅、雑音除去、および波形整形等の処理が行われ、振幅検出部２１７に送信される。
【００５７】
振幅検出部２１７では、発振器２１５から発振されて直接送信されてくる基準信号と信号処理回路２１１からの出力信号の乗算を乗算器で求め、この乗算の結果得られる信号の高調波成分をフィルタで除去して積分器２１９へ出力する。
【００５８】
積分器２１９では、振幅検出部２１７からの信号を積分し、可変利得増幅器２２１に利得を制御する利得制御信号を出力する。利得制御信号は、上述したように差動増幅器２５７の出力がゼロとなるように可変利得増幅器２２１の利得を制御（調整）するものである。
【００５９】
なお、各構成ユニットから出力される信号波形については、図６と同様であり、図６（ａ）が利得を増加させる場合、図６（ｂ）が利得を減少させる場合にそれぞれ対応している。
【００６０】
＜同時双方向通信時＞
同時双方向通信時の各スイッチの接続状態を、図４のブロック図を用いて説明する。スイッチＳＷ１では端子ａ１と端子ａ３を閉成してＩ／Ｏ回路２０１から出力されるウェアラブルコンピュータ５の送信データが送信回路２０３に達するようにする。スイッチＳＷ２では端子ｂ２−ｂ３間を接続して信号処理回路２１１からの出力信号が波形整形回路２２５およびＩ／Ｏ回路２０１を介してウェアラブルコンピュータ５に受信データとして届くようにする。スイッチＳＷ３では可変利得増幅器２２１の調整後の利得を一定に保つため、端子ｃ１と端子ｃ３を接続して固定電圧源２２３から信号（通常はゼロの信号）を印加する。これにより、利得調整時の信号値が保持されることになり、同時双方向通信を行っても、送信データが受信データに混入するのを防止することが可能になる。
【００６１】
以上説明した本発明の第２の実施形態によれば、上記第１の実施形態と同様の効果を得ることができる。
【００６２】
なお、上記各実施形態では、電界伝達媒体として生体を例に取り説明を行ったが、本発明に係るトランシーバの送受信時にデータに基づく電界を生じて伝達する電界伝達媒体は必ずしも生体に限定されるわけではない。
【００６３】
このように、本発明は上記同様の効果を奏する様々な実施の形態を含みうるものであることはいうまでもない。
【００６４】
【発明の効果】
以上説明した本発明によれば、同時双方向通信時に、受信側の回路に混入した送信回路の出力信号の影響を補償し、通信品質の向上を図ることが可能なトランシーバを提供することができる。
【００６５】
これにより、ウェアラブルコンピュータがより実現性の高いものとなる。
【図面の簡単な説明】
【図１】本発明の第１の実施形態に係るトランシーバ利得調整時の接続構成を示すブロック図である。
【図２】本発明の第１の実施形態に係るトランシーバ通信時の接続構成を示すブロック図である。
【図３】本発明の第２の実施形態に係るトランシーバ利得調整時の接続構成を示すブロック図である。
【図４】本発明の第２の実施形態に係るトランシーバ通信時の接続構成を示すブロック図である。
【図５】本発明の第２の実施形態に係るトランシーバにおける電界検出光学部の構成を示すブロック図である。
【図６】利得調整時の振幅モニタ部の各構成ユニットおよび制御信号発生部からそれぞれ出力される信号を示す説明図である。
【図７】従来法によるトランシーバの構成を示すブロック図である。
【図８】トランシーバを介してウェアラブルコンピュータを人間に装着して使用するときの例を示す説明図である。
【符号の説明】
１、２、３トランシーバ
５ウェアラブルコンピュータ
７生体
６１、６５、７１、７５出力信号
６３、７３基準信号
６７、７７信号
６９、７９制御信号
８０外部端末
９０ケーブル
１０１、２０１、３０１Ｉ／Ｏ回路
１０３、２０３、３０３送信回路
１０５、２０５、３０５送受信電極
１０７、２０７、３０７絶縁体
１０９、２０９、３０９電界検出光学部
１１１、２１１、３１１信号処理回路
１１３、２５７差動増幅器
１１５、２１５発振器
１１７、２１７振幅検出部
１１９、２１９積分器
１２１、２２１可変利得増幅器
１２３、２２３固定電圧源
１２５、２２５、３２５波形整形回路
２２７レーザダイオード（ＬＤ）
２２９電気光学素子
２３１、２３３、２４１電極
２３５偏光検出光学系
２３７、２４９、２５１コリメートレンズ
２３９第１波長板
２４３グランド電極
２４５第２波長板
２４７偏光ビームスプリッタ
２５３、２５５フォトダイオード
ＳＷ１、ＳＷ２、ＳＷ３スイッチ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a transceiver that transmits and receives information using an electric field induced in an electric field transmission medium that transmits an electric field, and more specifically, is used in data communication using a wearable computer that can be worn on a human body. Related to transceivers.
[0002]
[Prior art]
Due to the miniaturization and high performance of portable terminals, wearable computers that can be attached to living bodies have been attracting attention.
[0003]
Conventionally, data communication between such wearable computers has been proposed to transmit and receive data by connecting a transceiver to the computer and transmitting the electric field induced by the transceiver to the inside of a living body which is an electric field transmission medium. (For example, refer to Patent Document 1).
[0004]
FIG. 7 is a block diagram showing a configuration of a conventional transceiver. The transceiver 3 shown in the figure is connected to the wearable computer 5 via an I / O circuit 301 for inputting / outputting signals, and a transmission / reception electrode 305 is provided close to the living body 7 via an insulator 307. Yes. Information (data) transmitted from the wearable computer 5 is supplied from the transmission circuit 303 to the transmission / reception electrode 305, and an electric field is induced from the transmission / reception electrode 305 to the living body 7 through the insulator 307, and this electric field is transmitted through the living body 7. Then, the information transmitted from the wearable computer 5 is transmitted to the transceiver 3 provided in another part of the living body 7 or the transceiver 3 electrically connected by contact from the living body 7.
[0005]
When another transceiver 3 receives the electric field transmitted through the transceiver 3 in this way, the electric field received by the transmission / reception electrode 305 through the insulator 307 is converted into an electric signal by the electric field detection optical unit 309. To the signal processing circuit 311. The signal processing circuit 311 performs signal processing such as filtering and amplification on the electric signal from the electric field detection optical unit 309. After the signal processing, the waveform shaping of the data is further performed by the waveform shaping circuit 325, and the signal subjected to the series of processing is transmitted from the I / O circuit 301 to the wearable computer 5 as received data of the wearable computer 5.
[0006]
In this way, the transceiver 3 used for data communication between the wearable computers 5 induces an electric field based on information to be transmitted to the living body 7 as an electric field transmission medium, and transmits information using the induced electric field. Therefore, when receiving information, the transceiver 3 receives a signal using an electric field induced in the living body 7.
[0007]
FIG. 8 is an explanatory diagram showing an example in which the wearable computer 5 is used while being worn by a human being as an example of the living body 7. Wearable computers 5a, 5b, and 5c shown in the figure are attached to human arms, shoulders, trunks, and the like via correspondingly connected transceivers 3a, 3b, and 3c, and transmit / receive data to / from each other. Furthermore, when the tips of the limbs of the living body 7 are in contact with the transceivers 3′a and 3′b connected to the external terminal 80, which is an external device, via the cable 90, the wearable computers 5a, 5b, and 5c Data can be transmitted to and received from the external terminal 80.
[0008]
[Patent Document 1]
JP 2001-352298 A
[0009]
[Problems to be solved by the invention]
However, when the wearable computers using the transceivers described above need to perform simultaneous bidirectional communication, a signal output from the transmission circuit on the transmission side is mixed into the circuit on the reception side.
[0010]
The present invention has been made in view of the above, and an object of the present invention is to compensate for the influence of the output signal of the transmission circuit mixed in the circuit on the receiving side during simultaneous bidirectional communication and to improve the communication quality. Is to provide a simple transceiver.
[0011]
[Means for Solving the Problems]
  In order to achieve the above object, the present invention according to claim 1 induces an electric field based on information to be transmitted in an electric field transmission medium and transmits information using the induced electric field, while the electric field is transmitted. A transceiver for receiving information by receiving an electric field based on information to be received induced in a transmission medium, and transmitting a signal for inducing an electric field based on the information to be transmitted to the electric field transmission medium A transmitting means; a receiving means for receiving at least an electric field based on information to be received induced in the electric field transmission medium; and the receiving means detects an electric field based on the information to be received and electrically detects the detected electric field. An electric field detection means for converting into a signal, a differential amplifier for obtaining a difference between the signal output from the electric field detection means and the compensation signal, and amplifying the difference, via the electric field transmission medium When transmitting and receiving information, compensation signal generating means for generating a compensation signal for compensating for the influence of the signal transmitted by the transmitting means mixed in the signal received by the receiving means, the signal transmitted by the transmitting means, and the When performing transmission / reception of information via the electric field transmission medium with control means for outputting a control signal for controlling the characteristics of the compensation signal generation means to the compensation signal generation means based on a signal received by the reception means A first connection unit that connects the transmission unit and the control unit when controlling characteristics of the compensation signal generation unit in advance, while performing a connection capable of directly transmitting information to be transmitted to the transmission unit; When transmitting and receiving information, while connecting the receiving means and a waveform shaping circuit for shaping the waveform of the input signal, the characteristics of the compensation signal generating means are When the order control and summarized in that and a second connecting means for connecting the control means and the receiving means.
[0012]
  According to the first aspect of the present invention, the transmission means for transmitting the signal for inducing the electric field based on the information to be transmitted to the electric field transmission medium, and the electric field based on the information to be received induced in the electric field transmission medium. At least receiving means for receiving, and compensation signal generating means for generating a compensation signal for compensating for the influence of the signal transmitted by the transmitting means mixed in the signal received by the receiving means when transmitting and receiving information via the electric field transmission medium. By providing a transceiver comprising: a control means for outputting a control signal for controlling characteristics of the compensation signal generating means to the compensation signal generating means based on a signal transmitted by the transmitting means and a signal received by the receiving means. , Compensate the transmitter output signal mixed in the receiver, can improve the communication quality,
  The receiving means detects an electric field based on the information to be received, converts the detected electric field into an electric signal, and receives a signal output from the electric field detecting means and the compensation signal generating means. A difference amplifier for obtaining a difference between the compensation signals and amplifying the difference;
  When transmitting and receiving information via the electric field transmission medium, the information to be transmitted is connected so that it can be directly transmitted to the transmitting means, while when the characteristics of the compensation signal generating means are controlled in advance, the transmitting means and the The first connection means for connecting the control means and the waveform shaping circuit for shaping the waveform of the input signal when the information is transmitted / received are connected, while the characteristics of the compensation signal generating means When the control is performed in advance, the gist is provided with a second connection means for connecting the receiving means and the control means.
[0013]
  According to the present invention of claim 2, an electric field based on information to be transmitted is induced in an electric field transmission medium, and information is transmitted using the induced electric field, while reception induced by the electric field transmission medium is to be performed. A transceiver for receiving information by receiving an electric field based on information, wherein the transmitting means transmits a signal for inducing an electric field based on the information to be transmitted to the electric field transmission medium; and Receiving means for receiving at least an electric field based on induced information to be received, the receiving means is generated by a laser diode for generating a predetermined laser beam, an electric field based on the information to be received and the compensation signal generating means An electro-optic element that changes a polarization state of laser light incident from the laser diode by an electric field induced on the basis of the signal, and the electro-optic A polarization detection optical system that converts a polarization change amount of the laser light whose polarization state has changed by passing through the optical element into an intensity change of the laser light, and when transmitting and receiving information via the electric field transmission medium, Compensation signal generating means for generating a compensation signal for compensating for the influence of the signal transmitted by the transmitting means mixed in the signal received by the receiving means, a signal transmitted by the transmitting means, and a signal received by the receiving means And a control means for outputting a control signal for controlling the characteristics of the compensation signal generating means to the compensation signal generating means.
[0014]
  According to the third aspect of the present invention, an electric field based on information to be transmitted is induced in the electric field transmission medium, and information is transmitted using the induced electric field, while reception induced by the electric field transmission medium is to be performed. A transceiver for receiving information by receiving an electric field based on information, wherein the transmitting means transmits a signal for inducing an electric field based on the information to be transmitted to the electric field transmission medium; and The influence of the signal transmitted by the transmitting means mixed with the signal received by the receiving means when receiving and transmitting information via the electric field transmission medium at least when receiving the electric field based on the induced information to be received. Compensation signal generating means for generating a compensation signal for compensation, the compensation signal generating means based on a signal transmitted by the transmitting means and a signal received by the receiving means And a control means for outputting a control signal for controlling the characteristics of the compensation signal generating means, and the control means controls the compensation signal via the transmitting means when previously controlling the characteristics of the compensation signal generating means. An oscillator that oscillates an AC signal input to the generating means, an AC signal oscillated from the oscillator, and an output signal from the receiving means are multiplied, and a harmonic component of the signal obtained by the multiplication is removed to obtain an amplitude. An amplitude detector for detecting the signal, an integrator for generating the control signal based on the result of integrating the output signal from the amplitude detector, and a compensation signal generator for maintaining the characteristics of the compensation signal generator means constant. A fixed voltage source capable of applying a constant voltage to the means, and when transmitting and receiving the information, while connecting the integrator and the fixed voltage source, Transceiver characterized by comprising a third connecting means for connecting the integrator with the amplitude detection unit when controlling the characteristics in advance.
[0016]
Here, “when the characteristics of the compensation signal generating means are controlled in advance” means that not only the time before information transmission / reception, that is, the time before simultaneous bidirectional communication between different transceivers, but also the time of simultaneous bidirectional reception occurs. Including the case where communication is stopped and control is performed.
[0017]
  A fourth aspect of the present invention is that, in any one of the first to third aspects, the compensation signal generating means includes an amplifier, and the control means controls a gain as a characteristic of the amplifier. To do.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
[0021]
(First embodiment)
In the first embodiment of the present invention, the data transmitted from the transmission means is divided into a signal transmitted through the electric field induced in the living body and a signal to the compensation signal generation means, and the difference between the two is zero. By controlling the characteristics of the compensation signal generating means in advance, the transmission data signal is prevented from being mixed into the data received by the transceiver.
[0022]
FIG. 1 is a block diagram showing a configuration of a transceiver according to the first exemplary embodiment of the present invention. A transceiver 1 shown in FIG. 1 outputs data (information) transmitted from the wearable computer 5 and receives a received signal and outputs the received signal to the wearable computer 5, and transmission as a transmission means for transmitting data. The circuit 103, the transmitting / receiving electrode 105 made of a conductive member for inducing an electric field in the living body 7 which is an electric field transmission medium, and preventing current from flowing through the living body 7, and the risk of the metal allergy of the living body 7 by the transmitting / receiving electrode 105 In order to remove, there is provided an insulator 107 disposed between the transmission / reception electrode 105 and the living body 7, and at least a waveform shaping circuit 125 that performs waveform shaping of a signal received by the receiving means during communication and outputs the waveform to the I / O circuit 101. Of course, the transmission / reception electrodes can be divided into a transmission electrode and a reception electrode. In that case, two insulators are also provided corresponding to each electrode.
[0023]
In addition to the above, the transceiver 1 receives an electric field induced in the living body 7, optically detects the electric field, and then outputs the electric field from the electric field detection optical unit 109 and the electric field detection optical unit 109 that convert the electric signal. A signal processing circuit 111 that performs signal processing such as low noise amplification, noise removal, and waveform shaping on the signal is included, and these constitute electric field detection means.
[0024]
Of the electric field detection means, the electric field detection optical unit 109 detects an electric field by an electro-optical technique using laser light and an electro-optical element, and at least a laser diode and a LiNbO constituting a laser light source._ThreeAnd LiTaO_ThreeAnd an electro-optic element made of an electro-optic crystal (EO crystal: Electro Optic crystal) (not shown). As this electro-optic element, for example, it has sensitivity only to the electric field component in the direction perpendicular to the traveling direction of the laser light emitted from the laser diode, and the optical characteristics, that is, the birefringence index changes depending on the electric field strength, A laser beam whose polarization changes due to the change in birefringence can be used. In some cases, a change in polarization due to an inverse piezoelectric effect in which the crystal of the electro-optic element is distorted by an electric field is also included.
[0025]
The laser light whose polarization has been changed by passing through such an electro-optic element is subjected to polarization state adjustment using a wave plate, and then is incident on a polarization beam splitter to be separated into P-wave and S-wave. It is converted into intensity change. Each separated laser beam is condensed by a collimator (condensing lens) and then supplied to two photodiodes provided to convert the light into an electrical signal, for example, differentially amplifying the difference between them. Is output as an electrical signal related to the received electric field.
[0026]
It should be noted that the configuration and operation of the electric field detection optical unit 109 described above are merely examples, and the specific effect is obtained only when the electric field detection optical unit 109 applied to the transceiver 1 according to the present embodiment has such a configuration. Does not play.
[0027]
A feature of the transceiver 1 according to the present embodiment is that, in addition to the above configuration, a gain is a characteristic of a compensation signal generating unit that receives a signal from the transmission circuit 103 and generates a compensation signal that compensates for the influence of the signal. The adjustable variable gain amplifier 121 is provided.
[0028]
Along with the provision of the variable gain amplifier 121, the transceiver 1 further has the following configuration.
[0029]
The differential amplifier 113 that amplifies the difference between the compensation signal output from the variable gain amplifier 121 (the signal for compensating for the influence of the transmission circuit 103) and the signal output from the electric field detection means is combined with the electric field detection means. Receiving means is configured.
[0030]
The signal output from the differential amplifier 113 is output to control means for generating a control signal for adjusting the gain, which is a characteristic of the variable gain amplifier 121. The control means removes an oscillator 115 that oscillates with an AC signal having a predetermined frequency as a reference signal, a multiplier that multiplies the signal from the oscillator 115 and the signal from the differential amplifier 113, and harmonic components of the output signal of the multiplier. An amplitude detector 117 having a filter for integrating, an integrator 119 that integrates the output signal of the amplitude detector 117 and outputs a control signal for controlling the gain to the variable gain amplifier 121, and a constant gain of the variable gain amplifier 121 during communication It consists of a fixed voltage source 123 that generates a signal to maintain.
[0031]
Among these, the frequency of the AC signal oscillated from the oscillator 115 is assumed to be about 10 kHz (kilohertz) to 100 MHz (megahertz), but more preferably about 10 MHz. Where 1 kHz = 10^ThreeHz, 1MHz = 10⁶Hz.
[0032]
The transceiver 1 is provided with three switches SW1 (first connection means), SW2 (second connection means), and SW3 (third connection means) as connection means for switching circuit connections. The switch connection is switched by a connection switching control signal from the control circuit 161 connected to the I / O circuit 101. In addition, in FIG. 1 etc., it has shown that the location described with the circle | round | yen of A is connected with wiring. A switching control signal for switching the switch generated from the control circuit 161 may be generated by an operation from the wearable computer 5, or a switching control signal input unit is appropriately provided in the transceiver 1, and this switching control signal input unit is provided. You may make it generate | occur | produce using. Needless to say, the configuration of each switch and control circuit as connection switching means is not limited to that described here.
[0033]
In this embodiment, since it is assumed that different wearable computers 5 perform simultaneous bidirectional communication, the transceiver 1 provided close to each wearable computer 5 outputs from the transmission circuit 103 during simultaneous bidirectional communication. May be mixed into the receiving side circuit of the same transceiver 1. Therefore, in order to suppress this influence, control for compensating for the influence of the signal of the transmission circuit 103 is performed in advance before performing simultaneous bidirectional communication, or is appropriately performed every time a malfunction occurs. This control is performed by adjusting the gain of the variable gain amplifier 121. Hereinafter, the operation of the transceiver 1 will be described separately for gain adjustment and simultaneous bidirectional communication.
[0034]
<During gain adjustment>
First, connection of each switch at the time of gain adjustment shown in FIG. 1 will be described. The switch SW1 connects the terminals a2 to a3 among the three terminals so that the signal from the oscillator 115 reaches the transmission circuit 103. In the switch SW2, the terminal b1 and the terminal b3 are closed so that the output signal of the differential amplifier 113 is output to the amplitude detector 117. In the switch SW3, the terminal c2 and the terminal c3 are closed so that the signal from the amplitude detector 117 is output to the integrator 119. By controlling the connection of the switches as described above, the amplitude detection unit 117, the integrator 119, and the variable gain amplifier 121 constitute a negative feedback circuit to the differential amplifier 113.
[0035]
The signal of the oscillator 115 is sent to the transmission circuit 103, the signal sent to the differential amplifier 113 via the variable gain amplifier 121, and the signal to the differential amplifier 113 via the living body 7, the electric field detection optical unit 109, and the signal processing circuit 111. Divided into signals to be sent. The difference between the two signals is obtained by the differential amplifier 113, and a signal obtained by amplifying the difference is input to the amplitude detector 117 via the switch SW2.
[0036]
A signal (reference signal) output directly from the oscillator 115 to the amplitude detection unit 117 and a signal output from the differential amplifier 113 are obtained by obtaining a product of both in a multiplier in the amplitude detection unit 117. Harmonic components are removed by a filter in the amplitude detector 117 and output. The output signal of the amplitude detector 117 is integrated by the integrator 119, and the control signal for the variable gain amplifier 121 is generated to adjust the gain of the variable gain amplifier 121. The gain at this time is adjusted so that the output of the differential amplifier 113 becomes zero. In other words, by adjusting the gain in this way, a signal that is input from the transmission circuit 103 to the differential amplifier 113 via the variable gain amplifier 121 and mixed into the reception side from the transmission circuit 103 via the living body 7 Can be equivalent.
[0037]
FIG. 6 is an explanatory diagram showing an example of signal waveforms output from each component unit until a gain control signal at the time of gain adjustment is generated.
[0038]
Among these, FIG. 6A shows a change in signal waveform when the gain of the variable gain amplifier 121 is small. In this case, the output signal 61 of the differential amplifier 113 and the reference signal 63 from the oscillator 115 are in phase. Therefore, the output signal 65 obtained by multiplying both by the multiplier in the amplitude detector 117 has a waveform having a displacement only in the positive direction. A signal 67 is obtained by removing the harmonic component of the output signal 65 using a filter in the amplitude detector 117. After the signal 67 is integrated by the integrator 119, a control signal 69 for increasing the gain is output from the integrator 119 to the variable gain amplifier 121. As a result, the output signal of the differential amplifier 113 becomes zero.
[0039]
FIG. 6B is an explanatory diagram showing changes in the signal waveform when the gain is large. In this case, the output signal 71 of the differential amplifier 113 is in reverse phase with the reference signal 73. Therefore, the output signal 75 obtained by multiplying both by the multiplier in the amplitude detector 117 has a displacement only in the negative direction, and the signal 77 obtained by removing the harmonic component of the output signal 75 using the filter described above. As a result of the integration by the integrator 119, a control signal 79 for reducing the gain so that the output of the differential amplifier 113 becomes zero is output from the integrator 119 to the variable gain amplifier 121.
[0040]
<Simultaneous bidirectional communication>
First, the connection state of each switch during simultaneous bidirectional communication will be described with reference to the block diagram of FIG. In the switch SW1, the terminals a1 and a3 are closed so that the transmission data of the wearable computer 5 output from the I / O circuit 101 reaches the transmission circuit 103. The switch SW2 connects the terminals b2 and b3 so that the output signal from the differential amplifier 113 reaches the wearable computer 5 as received data via the waveform shaping circuit 125 and the I / O circuit 101. In the switch SW3, in order to keep the adjusted gain of the variable gain amplifier 121 constant, the terminal c1 and the terminal c3 are connected to apply a signal (usually a zero signal) from the fixed voltage source 123 to the variable gain amplifier 121.
[0041]
As a result, the transmission data information is canceled by the variable gain amplifier 121 and the differential amplifier 113, so that it is possible to prevent the transmission data from being mixed into the reception data even when simultaneous bidirectional communication is performed.
[0042]
According to the first embodiment of the present invention described above, by transmitting (adjusting) the gain of the variable gain amplifier in advance, the transmission data signal transmitted by itself to the data received by the transceiver during simultaneous bidirectional communication. Can be prevented, and the communication quality can be improved.
[0043]
The transceiver according to the present embodiment, for example, in an environment in which workers are working while having a conversation with each other at the time of a disaster, for example, can be provided in an oxygen mask, a gas mask, etc., so that conversation during the work can be performed smoothly. It becomes possible.
[0044]
(Second Embodiment)
In the transceiver according to the second embodiment of the present invention, the output signal from the variable gain amplifier is also input to the electric field detection means, and the gain is obtained using the electric field based on the output signal and the electric field transmitted through the living body 7. Coordinates and performs simultaneous bidirectional communication.
[0045]
FIGS. 3 and 4 are block diagrams respectively showing connection states during gain adjustment and simultaneous bidirectional communication of the transceiver according to the second embodiment of the present invention. In the transceiver 2 shown in both figures, an I / O circuit 201, a transmission circuit 203, a transmission / reception electrode 205, an insulator 207, a signal processing circuit 211, an oscillator 215, an amplitude detection unit 217, an integrator 219, a fixed voltage source 223, and waveform shaping. The circuit 225 and the control circuit 261 have functions similar to the corresponding parts (see FIGS. 1 and 2) of the transceiver 1 according to the first embodiment. Therefore, for these corresponding parts, the last two digits are shown in alignment with FIG.
[0046]
The first, second, and third connection means are also provided with switches SW1, SW2, and SW3, respectively, as in the first embodiment, and control of these switches is performed by the control circuit. Of course, the process is also performed via H.261 (the same applies to the point that the circle A in FIGS. 3 and 4 indicates the connection of the circuit).
[0047]
Further, the value of the frequency oscillated by the oscillator 215, the point that the transmission / reception electrode may be divided into the transmission electrode and the reception electrode, and the like are the same as in the first embodiment.
[0048]
In the variable gain amplifier 221 as the compensation signal generating means, a signal whose output is inverted from that of the signal transmitted from the transmission circuit 203, that is, a signal whose phase is inverted is output as a compensation signal. Unlike the first embodiment, this signal is output together with the signal processing circuit 211 to the electric field detection optical unit 209 that forms a receiving unit.
[0049]
FIG. 5 is an explanatory diagram showing a detailed configuration of the electric field detection optical unit 209. An electric field detection optical unit 209 shown in the figure detects an electric field by an electro-optic technique using laser light and an electro-optic crystal, and includes the laser diode (LD) 227 constituting the laser light source and the first embodiment. The electro-optic element 229 made of the same electro-optic crystal as that described in the embodiment is included. The electro-optical element 229 has sensitivity only to an electric field component perpendicular to the traveling direction of the laser light from the laser diode 227, and the optical characteristics, that is, the birefringence changes depending on the electric field strength. Changes the polarization state of the laser beam.
[0050]
Of the two side surfaces (both side surfaces facing in the left-right direction in the figure) of the electro-optic element 229 parallel to the laser light incident direction, two electrodes 231 and 233 are provided on one side (right side in the figure) An electrode 241 connected to the ground electrode 243 is provided on the side surface (left side in the figure). The electrode 231 receives the compensation signal output from the variable gain amplifier 221, and induces an electric field corresponding to the potential difference with the electrode 241 generated by the compensation signal in a direction orthogonal to the laser light incident direction inside the electro-optic element 229. The electrode 233 receives a signal based on the electric field that is induced in the living body 7 and received through the transmitting / receiving electrode 205, and induces the electric field received from the living body 7 in a direction orthogonal to the laser light incident direction. The compensation signal output from the variable gain amplifier 221 is a signal whose phase is inverted. This prevents the transmission data transmitted from the transmission circuit 203 from being mixed into the reception data if the gain of the variable gain amplifier 221 is controlled in advance so as to cancel the electro-optic effect caused by the two electric fields described above. This is because it can be done. Hereinafter, a specific configuration of the electric field detection optical unit 209 for that purpose will be further described.
[0051]
The laser light output from the laser diode 227 is converted into parallel light through the collimator lens 237, and the laser light that has become parallel light is adjusted in polarization state by the first wave plate 239 and enters the electro-optical element 229. The polarization state of the laser light incident on the electro-optic element 229 changes as the birefringence, which is the optical characteristic of the electro-optic element 229, changes due to the two electric fields described above.
[0052]
The laser light whose polarization state has been changed in this manner is adjusted in polarization state by the second wave plate 245 and is incident on the polarization beam splitter 247. The polarization beam splitter 247 separates the laser light incident from the second wave plate 245 into P wave and S wave, and converts them into a change in light intensity. The laser light separated into the P-wave component and the S-wave component by the polarization beam splitter 247 is condensed by the collimating lenses 249 and 251 respectively, and then supplied to the photodiodes 253 and 255 to be converted into electric signals. . Thereafter, the two electrical signals are input to the differential amplifier 257, the difference between which is obtained, amplified, and output to the signal processing circuit 211.
[0053]
The operation of the transceiver 2 having the above configuration will be described separately for gain adjustment of the variable gain amplifier 221 and simultaneous bidirectional communication.
[0054]
<During gain adjustment>
First, the connection state of each switch at the time of gain adjustment shown in FIG. 3 will be described. The switch SW1 connects the terminals a2 to a3 among the three terminals so that the signal from the oscillator 215 reaches the transmission circuit 203. In the switch SW2, the terminal b1 and the terminal b3 are closed so that the output signal of the signal processing circuit 211 is output to the amplitude detector 217. In the switch SW3, the terminal c2 and the terminal c3 are closed so that the signal from the amplitude detector 217 is output to the integrator 219. By controlling the connection of the switches as described above, the amplitude detector 217, the integrator 219, the variable gain amplifier 221 and the electro-optic element 229 substantially constitute a negative feedback circuit.
[0055]
The AC signal oscillated from the oscillator 215 is output as a reference signal by dividing the transmission circuit 203 and the amplitude detector 217. Among these signals, the reference signal output to the transmission circuit 203 reaches the electrode 231 of the electric field detection optical unit 209 via the variable gain amplifier 221, and generates an electric field orthogonal to the incident direction of the laser light incident on the electro-optic element 229. It induces in the electro-optic element 229. Here, the variable gain amplifier 221 outputs a compensation signal obtained by inverting the output with respect to the signal arriving from the transmission circuit 203 to the electrode 231. By inverting the output in this way, transmission is performed by adjusting the gain so that the output of the differential amplifier 257 in the polarization detection optical system 235 becomes zero by the electro-optic effect combined with the electric field received from the living body 7. Data mixing can be prevented.
[0056]
A signal whose difference is amplified by the differential amplifier 257 is transmitted to the signal processing circuit 211, subjected to processing such as low noise amplification, noise removal, and waveform shaping, and transmitted to the amplitude detection unit 217.
[0057]
In the amplitude detection unit 217, multiplication of the reference signal oscillated from the oscillator 215 and directly transmitted and the output signal from the signal processing circuit 211 is obtained by a multiplier, and the harmonic component of the signal obtained as a result of the multiplication is filtered. Remove and output to integrator 219.
[0058]
The integrator 219 integrates the signal from the amplitude detector 217 and outputs a gain control signal for controlling the gain to the variable gain amplifier 221. As described above, the gain control signal controls (adjusts) the gain of the variable gain amplifier 221 so that the output of the differential amplifier 257 becomes zero.
[0059]
The signal waveforms output from each component unit are the same as those in FIG. 6, and FIG. 6 (a) corresponds to the case where the gain is increased, and FIG. 6 (b) corresponds to the case where the gain is decreased. .
[0060]
<Simultaneous bidirectional communication>
The connection state of each switch during simultaneous bidirectional communication will be described with reference to the block diagram of FIG. In the switch SW1, the terminals a1 and a3 are closed so that the transmission data of the wearable computer 5 output from the I / O circuit 201 reaches the transmission circuit 203. The switch SW2 connects the terminals b2-b3 so that the output signal from the signal processing circuit 211 reaches the wearable computer 5 as received data via the waveform shaping circuit 225 and the I / O circuit 201. In the switch SW3, in order to keep the adjusted gain of the variable gain amplifier 221 constant, the terminal c1 and the terminal c3 are connected and a signal (usually a zero signal) is applied from the fixed voltage source 223. As a result, the signal value at the time of gain adjustment is held, and it is possible to prevent transmission data from being mixed into reception data even if simultaneous bidirectional communication is performed.
[0061]
According to the second embodiment of the present invention described above, the same effects as those of the first embodiment can be obtained.
[0062]
In each of the above-described embodiments, the living body is taken as an example of the electric field transmission medium. However, the electric field transmission medium that generates and transmits an electric field based on data during transmission / reception of the transceiver according to the present invention is not necessarily limited to the living body. Do not mean.
[0063]
Thus, it goes without saying that the present invention can include various embodiments that exhibit the same effects as described above.
[0064]
【The invention's effect】
According to the present invention described above, it is possible to provide a transceiver capable of compensating for the influence of the output signal of the transmission circuit mixed in the circuit on the receiving side during simultaneous bidirectional communication and improving communication quality. .
[0065]
This makes the wearable computer more feasible.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a connection configuration during transceiver gain adjustment according to a first embodiment of the present invention.
FIG. 2 is a block diagram showing a connection configuration during transceiver communication according to the first embodiment of the present invention.
FIG. 3 is a block diagram showing a connection configuration during transceiver gain adjustment according to a second embodiment of the present invention.
FIG. 4 is a block diagram showing a connection configuration during transceiver communication according to a second embodiment of the present invention.
FIG. 5 is a block diagram showing a configuration of an electric field detection optical unit in a transceiver according to a second embodiment of the present invention.
FIG. 6 is an explanatory diagram showing signals output from each component unit of the amplitude monitor unit and the control signal generation unit during gain adjustment;
FIG. 7 is a block diagram showing a configuration of a transceiver according to a conventional method.
FIG. 8 is an explanatory diagram showing an example when a wearable computer is worn and used by a person via a transceiver.
[Explanation of symbols]
1, 2, 3 Transceiver
5 Wearable computers
7 Living body
61, 65, 71, 75 Output signal
63, 73 Reference signal
67, 77 signals
69, 79 Control signal
80 External terminal
90 cable
101, 201, 301 I / O circuit
103, 203, 303 Transmitter circuit
105, 205, 305 Transmit / receive electrode
107, 207, 307 Insulator
109, 209, 309 Electric field detection optical unit
111, 211, 311 Signal processing circuit
113, 257 differential amplifier
115, 215 oscillator
117, 217 Amplitude detector
119, 219 integrator
121, 221 Variable gain amplifier
123, 223 Fixed voltage source
125, 225, 325 Waveform shaping circuit
227 Laser diode (LD)
229 electro-optic element
231,233,241 electrodes
235 Polarization detection optical system
237, 249, 251 Collimating lens
239 First wave plate
243 Ground electrode
245 Second wave plate
247 Polarizing beam splitter
253, 255 Photodiode
SW1, SW2, SW3 switch

Claims

By inducing an electric field based on information to be transmitted in the electric field transmission medium and transmitting information using the induced electric field, while receiving an electric field based on the information to be received induced in the electric field transmission medium. A transceiver for receiving information,
Transmitting means for transmitting a signal for inducing an electric field based on the information to be transmitted to the electric field transmission medium;
Receiving means for receiving at least an electric field based on information to be received induced in the electric field transmission medium;
The receiving means detects an electric field based on the information to be received, converts the detected electric field into an electric signal, and obtains a difference between the signal output from the electric field detecting means and the compensation signal; A differential amplifier for amplifying this difference, and
Compensation signal generating means for generating a compensation signal for compensating for the influence of the signal transmitted by the transmitting means mixed in the signal received by the receiving means when transmitting and receiving information via the electric field transmission medium;
Control means for outputting to the compensation signal generating means a control signal for controlling characteristics of the compensation signal generating means based on the signal transmitted by the transmitting means and the signal received by the receiving means;
When transmitting and receiving information via the electric field transmission medium, the information to be transmitted is connected so that it can be directly transmitted to the transmitting means, while when the characteristics of the compensation signal generating means are controlled in advance, the transmitting means and the First connection means for connecting the control means;
When transmitting and receiving the information, the receiving means is connected to a waveform shaping circuit for shaping the waveform of the input signal, while when the characteristics of the compensation signal generating means are controlled in advance, the receiving means and the control means A second connecting means for connecting
A transceiver comprising:

By inducing an electric field based on information to be transmitted in the electric field transmission medium and transmitting information using the induced electric field, while receiving an electric field based on the information to be received induced in the electric field transmission medium. A transceiver for receiving information,
Transmitting means for transmitting a signal for inducing an electric field based on the information to be transmitted to the electric field transmission medium;
Receiving means for receiving at least an electric field based on information to be received induced in the electric field transmission medium;
The receiving means includes a laser diode that generates a predetermined laser beam and a laser that is incident from the laser diode by an electric field based on the information to be received and an electric field that is induced based on a signal generated by the compensation signal generating means. An electro-optical element that changes the polarization state of the light, and a polarization detection optical system that converts the polarization change amount of the laser light whose polarization state has changed by passing through the electro-optical element into an intensity change of the laser light. And
Compensation signal generating means for generating a compensation signal for compensating for the influence of the signal transmitted by the transmitting means mixed in the signal received by the receiving means when transmitting and receiving information via the electric field transmission medium;
Control means for outputting a control signal for controlling the characteristics of the compensation signal generating means to the compensation signal generating means based on a signal transmitted by the transmitting means and a signal received by the receiving means. And transceiver.

By inducing an electric field based on information to be transmitted in the electric field transmission medium and transmitting information using the induced electric field, while receiving an electric field based on the information to be received induced in the electric field transmission medium. A transceiver for receiving information,
Transmitting means for transmitting a signal for inducing an electric field based on the information to be transmitted to the electric field transmission medium;
Receiving means for receiving at least an electric field based on information to be received induced in the electric field transmission medium;
Compensation signal generating means for generating a compensation signal for compensating for the influence of the signal transmitted by the transmitting means mixed in the signal received by the receiving means when transmitting and receiving information via the electric field transmission medium;
Control means for outputting to the compensation signal generating means a control signal for controlling characteristics of the compensation signal generating means based on the signal transmitted by the transmitting means and the signal received by the receiving means;
The control means includes an oscillator that oscillates an AC signal that is input to the compensation signal generation means via the transmission means when previously controlling characteristics of the compensation signal generation means, and an AC signal that is oscillated from the oscillator. Based on the result of integrating the output signal from the amplitude detection unit, which detects the amplitude by taking the multiplication with the output signal from the receiving means and removing the harmonic component of the signal obtained by this multiplication An integrator for generating the control signal, and a fixed voltage source capable of applying a constant voltage to the compensation signal generating means in order to keep the characteristics of the compensation signal generating means constant,
A third connection for connecting the amplitude detector and the integrator when controlling the characteristics of the compensation signal generating unit in advance while connecting the integrator and the fixed voltage source when transmitting and receiving the information. Means,
A transceiver comprising:

4. The transceiver according to claim 1, wherein the compensation signal generating means comprises an amplifier, and the control means controls a gain as a characteristic of the amplifier.