JP4078807B2 - RFID antenna - Google Patents

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Publication number
JP4078807B2
JP4078807B2 JP2001036706A JP2001036706A JP4078807B2 JP 4078807 B2 JP4078807 B2 JP 4078807B2 JP 2001036706 A JP2001036706 A JP 2001036706A JP 2001036706 A JP2001036706 A JP 2001036706A JP 4078807 B2 JP4078807 B2 JP 4078807B2
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core member
magnetic core
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columnar portion
laminated
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JP2002204122A (en
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貴則 遠藤
誠朗 八幡
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Mitsubishi Materials Corp
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Mitsubishi Materials Corp
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Description

【０００１】
【発明の属する技術分野】
本発明は、ＲＦＩＤ（無線周波数識別：Radio Frequency Identification）技術を利用したタグや、このタグに記憶された情報を読出す質問器に用いられるアンテナに関するものである。
【０００２】
【従来の技術】
従来、バス等の行先情報が入力されたＲＦＩＤタグがバス等に取付けられ、時刻表情報が入力されたＲＦＩＤタグが乗り場の時刻表示板のベースに埋設され、バス等の乗り場への誘導情報が入力されたＲＦＩＤタグが歩行路の点字誘導タイルに埋設され、更に上記各ＲＦＩＤタグが発信する情報を杖状のアンテナを介して質問器が読取るように構成された非接触認識ラベルを利用した交通情報認識装置が開示されている（特開平１１−１４３４１８号）。
このように構成された非接触認識ラベルを利用した交通情報認識装置では、視覚障害者が歩行路の点字誘導タイル上を歩行すると、このタイルに埋設されたＲＦＩＤタグの発信する誘導情報がアンテナを介して質問器により得られるので、視覚障害者はバスの乗場までの道程を確実に知ることができる。またバスの乗場に到着し、杖状アンテナを時刻表示板のベースに向けると、このベースに埋設されたＲＦＩＤタグの発信する時刻表情報がアンテナを介して質問器により得られる。更にバスが乗場に到来したときに杖状アンテナをバスに向けると、このバスに取付けられたＲＦＩＤタグの発信する行先情報がアンテナを介して質問器により得られるので、このバスが乗るべきバスであるか否かを知ることができる。このように視覚障害者等は交通機関の乗場までの道順や時刻表情報などを自動的に得られるので、道や交通機関を間違えずにスムーズに目的地まで行くことができるようになっている。
【０００３】
【発明が解決しようとする課題】
しかし、上記従来の特開平１１−１４３４１８号に示された非接触認識ラベルを利用した交通情報認識装置では、質問器に接続された杖状のアンテナの作動距離を大きくするには、フェライト等により形成されかつコイルが巻回される磁芯部材の直径及び長さのいずれか一方又は双方を大きくする必要があり、この磁芯部材を大型化すると、杖状のアンテナが重くなって携帯性を損う不具合があった。
本発明の目的は、軽量であって、しかも作動距離が長く、携帯性に優れた、ＲＦＩＤ用アンテナを提供することにある。
本発明の別の目的は、構造が簡単であって、しかも磁芯部材内に電子部品や電池等を収容可能なスペースを確保することにより小型化できる、ＲＦＩＤ用アンテナを提供することにある。
【０００４】
【課題を解決するための手段】
本発明者らは、理論的考察と実験を繰返した結果、ＲＦＩＤタグの作動距離（ＲＦＩＤ質問器のアンテナ及びＲＦＩＤタグのアンテナ間の距離であって、ＲＦＩＤタグが作動可能な最大距離）がＲＦＩＤ質問器又はＲＦＩＤタグのアンテナの磁芯部材の長さとその両端部の外周の形状寸法が変わらなければ殆ど変化しないことを見出した。即ち、磁芯部材を一定断面積の柱状ではなく、長さと両端部の外周を同一にすれば、中央を細く形成したり、両端部近傍に一対の穴を形成したり、或いは全長にわたって通孔を形成しても、上記作動距離が殆ど変化しないことを見出して、本発明をなすに至った。
【０００５】
また本発明者らは、ＲＦＩＤ質問器のアンテナの一端が常にＲＦＩＤタグのアンテナの一端に対向するように設定されている場合、ＲＦＩＤ質問器のアンテナ又はＲＦＩＤタグのアンテナの磁芯部材の長さとその一端の外周の形状寸法が変わらなければ、ＲＦＩＤタグの作動距離は殆ど変化しないことを見出した。即ち、磁芯部材を一定断面積の柱状ではなく、長さと一端の外周を同一にすれば、他端側を細く形成したり、他端側にスリットや穴を形成しても、上記作動距離が殆ど変化しないことを見出して、本発明をなすに至った。
【０００６】
請求項１に係る発明は、図４に示すように、磁芯部材３４にコイル本体１６を巻回することにより形成されたＲＦＩＤ用アンテナの改良である。
その特徴ある構成は、磁芯部材３４が、磁性材料からなる粉末若しくはフレーク及びプラスチックの複合材により或いはフェライトにより柱状に形成されコイル本体１６が巻回される柱状部１４ａと、柱状部１４ａの両端に設けられ柱状部１４ａから離れるに従って次第に太くなる一対のテーパ部１４ｂ，１４ｂと、一対のテーパ部１４ｂ，１４ｂのいずれか一方又は双方に形成され磁芯部材３４の端面から柱状部１４ａに向うに従って穴径が小さくなるテーパ穴３４ｃ，３４ｃとを有するところにある。
【０００７】
この請求項１に記載されたＲＦＩＤ用アンテナでは、一対のテーパ部１４ｂ，１４ｂの最も太い部分を直径とする従来の柱状の磁芯部材と比べて、本発明の磁芯部材１４は中央から両端近傍まで従来の磁芯部材より細く形成されており、一対のテーパ部１４ｂ，１４ｂのいずれか一方又は双方にテーパ穴３４ｃ，３４ｃを形成したので軽く、しかもその磁芯部材１４を用いたアンテナ１１の作動距離は従来の磁芯部材を用いたアンテナの作動距離と略同一となる。また磁芯部材１４の柱状部１４ａで磁束の通過する断面が小さくなるため、コイル本体１６の巻数を増やす必要があるけれども、コイル本体１６は細い柱状部１４ａに巻回されるため、コイル本体１６の全長が短くなってその電気抵抗が小さくなり、この磁芯部材１４を用いたアンテナ１１とコンデンサにより構成される共振回路のＱ値が大きくなって共振の幅が鋭くなる。
ここで、Ｑ値とは、電波の角周波数をωとし、アンテナ及びコンデンサにて構成される共振回路の抵抗値をｒとし、コイル本体の自己インダクタンスをＬとするとき、ωＬ／ｒで定義される数値であり、Ｑ値が高いほど渦電流等による損失が少なくなり、共振の幅が鋭くなることが知られている。
【００１０】
請求項２に係る発明は、図８に示すように、磁芯部材５４が、磁性材料からなる粉末若しくはフレーク及びプラスチックの複合材により或いはフェライトにより柱状に形成されコイル本体１６が巻回される柱状部５４ａと、柱状部５４ａの両端にそれぞれ接着されアモルファスの積層体或いはアモルファス箔及びプラスチックフィルムの積層体により形成された一対の積層部５４ｂ，５４ｂとを有することを特徴とする。
この請求項２に記載されたＲＦＩＤ用アンテナでは、磁芯部材５４の中央の柱状部５４ａで渦電流が発生しないため、高周波損失は少なく、この磁芯部材５４を用いたアンテナ５１とコンデンサにより構成される共振回路のＱ値は低下しない。また一対の積層部５４ｂ，５４ｂは軽量であるため、アンテナ５１全体の重量を低減できる。
【００１１】
請求項３に係る発明は、請求項２に係る発明であって、更に図８に示すように、柱状部５４ａの横断面積が一対の積層部５４ｂ，５４ｂの横断面積より小さく形成されたことを特徴とする。
この請求項３に記載されたＲＦＩＤ用アンテナでは、比較的比重の大きな柱状部５４ａを細く形成しかつ比較的大径の一対の積層部５４ｂ，５４ｂの比重を小さくすることにより、アンテナ５１全体の重量を更に低減できる。また柱状部５４ａで磁束の通過する断面が小さくなるため、コイル本体１６の巻数を増やす必要があるけれども、コイル本体１６は細い柱状部５４ａに巻回されるため、コイル本体１６の全長が短くなってその電気抵抗が小さくなり、この磁芯部材５４を用いたアンテナ５１とコンデンサにより構成される共振回路のＱ値が大きくなってその共振の幅が鋭くなる。
【００１３】
請求項４に係る発明は、図１３に示すように、磁芯部材７４が、磁性材料からなる粉末若しくはフレーク及びプラスチックの複合材により或いはフェライトにより柱状に形成された柱状部７４ａと、柱状部７４ａの一端に接続されアモルファス箔の積層体或いはアモルファス箔及びプラスチックフィルムの積層体により柱状に形成された積層部７４ｂとを有し、積層部７４ｂが、柱状部７４ａの一端に接着剤を用いて直接接続されるか或いは柱状部７４ａ及び積層部７４ｂをベース板に接着剤を用いて接着することにより柱状部７４ａの一端に間接的に接続されることを特徴とする。
この請求項４に記載されたＲＦＩＤ用アンテナでは、磁芯部材７４の積層部７４ｂを比重の比較的小さいアモルファス箔及びプラスチックフィルムの積層体にて形成すれば、磁芯部材７４をある程度軽くすることができる。また磁芯部材７４には上記請求項６の磁芯部材より渦電流が発生し難くかつ高周波損失が少なくなるため、この磁芯部材７４を用いたアンテナ７１とコンデンサにより構成される共振回路のＱ値は請求項６の磁芯部材を用いた共振回路のＱ値より高くなる。
【００１４】
請求項５に係る発明は、請求項４に係る発明であって、更に図１６に示すように、積層部８４ｂの横断面積が柱状部７４ａの横断面積より小さく形成されたことを特徴とする。
この請求項５に記載されたＲＦＩＤ用アンテナでは、積層部８４ｂの横断面積が柱状部７４ａの横断面積より小さいため、積層部８４ｂに沿って電子部品や電池等を収容するスペースを確保できる。
【００１５】
請求項６に係る発明は、請求項４に係る発明であって、更に図１９に示すように、積層部が、柱状部７４ａの一端にこの柱状部７４ａの長手方向に直交する方向に所定のスペース９４ｃをあけた状態でそれぞれ接続された一対の積層部９４ｂ，９４ｂであることを特徴とする。
この請求項６に記載されたＲＦＩＤ用アンテナでは、一対の積層部９４ｂ，９４ｂの間の所定のスペース９４ｃに電子部品や電池等を収容することができる。また積層部９４ｂ，９４ｂの外周は上記スペース９４ｃにアモルファス箔の積層体などが充填された積層部と同一であるため、磁芯部材９４の性能は殆ど変わらない。
【００１６】
請求項７に係る発明は、図２２に示すように、磁芯部材１０４が、磁性材料からなる粉末若しくはフレーク及びプラスチックの複合材により或いはフェライトにより柱状に形成された柱状部１０４ａと、柱状部１０４ａの一端に接着剤を用いて直接接続されアモルファス箔の積層体或いはアモルファス箔及びプラスチックフィルムの積層体により筒状に形成された積層部１０４ｂとを有することを特徴とする。
この請求項７に記載されたＲＦＩＤ用アンテナでは、筒状の積層部１０４内に電子部品や電池等を収容することができる。
【００１７】
請求項８に係る発明は、図２５に示すように、磁芯部材１１４が、磁性材料からなる粉末若しくはフレーク及びプラスチックの複合材により或いはフェライトにより柱状に形成された柱状部１０４ａと、柱状部１０４ａの一端に接着剤を用いて直接接続されアモルファス箔の積層体或いはアモルファス箔及びプラスチックフィルムの積層体により半筒状に形成された積層部１１４ｂとを有することを特徴とする。
この請求項８に記載されたＲＦＩＤ用アンテナでは、積層部１１４ｂの横断面積が柱状部１０４ａの横断面積より小さいため、積層部１１４ｂに沿って電子部品や電池等を収容するスペースを確保できる。
【００１８】
次に第１の参考の形態を図面に基づいて説明する。
図１〜図３に示すように、この参考の形態のＲＦＩＤ用アンテナ１１は視覚障害者の携帯するステッキ１２の先端に内蔵されかつＲＦＩＤ質問器１３に接続された質問器用アンテナである。このアンテナ１１は磁芯部材１４と、この磁芯部材１４に巻回されたコイル本体１６とを有する。ＲＦＩＤ質問器１３は質問器用アンテナ１１を介してＲＦＩＤタグ１７のＩＣチップ１９のメモリ１９ｆに記憶された情報を読出すように構成される（図３）。ＲＦＩＤタグ１７は駅のホームの乗車位置に埋設されたり、駅の階段の最上段又は最下段に埋設されたり、バスの停留所に埋設されたり、遊園地のチケット売場や各遊戯施設の入口近傍に埋設されたり、或いは音楽堂などのチケット売場や各座席近傍に埋設される。タグ１７のＩＣチップ１９のメモリ１９ｆにはタグ１７の埋設された場所に関する情報（タグ１７固有の情報）が記憶され、ＩＣチップ１９にはタグ用アンテナ１８が電気的に接続される。
【００１９】
質問器用アンテナ１１の磁芯部材１４は円柱状に形成された柱状部１４ａと、柱状部１４ａの両端に設けられた一対のテーパ部１４ｂ，１４ｂとを有する（図１及び図２）。テーパ部１４ｂは柱状部１４ａから離れるに従って次第に太くなるように形成される。磁芯部材１４ａは金属又はフェライトの粉末又はフレークとプラスチックとの複合材により形成される。金属の粉末としては、カーボニル鉄粉末，鉄又はパーマロイ等のアトマイズ粉末，還元鉄粉末等が用いられる。また金属のフレークとしては、上記金属の粉末をボールミル、ローラ等で機械的に扁平化して得られたフレークや、鉄系又はコバルト系合金の溶湯を水冷銅に衝突させて得られたアモルファスフレークなどが用いられる。更にプラスチックとしては加工性の良い熱可塑性のプラスチックを用いたり、或いは耐熱性の良い熱硬化性のプラスチックを用いたりすることができる。なお、柱状部１４ａは円柱状ではなく角柱状に形成してもよい。
【００２０】
またＲＦＩＤ質問器１３は所定の質問信号を載せた電波を質問器用アンテナ１１から発信しかつタグ用アンテナ１８の発信したタグ１７固有の情報を載せた電波を受けてメモリ２１に記憶する処理部２２と、このメモリ２１に記憶された情報を音声信号に変換する音声変換部２３と、この音声信号を音声に変換するイヤホン２４とを備える（図３）。処理部２２は質問器用アンテナ１１に接続されバッテリ（図示せず）を内蔵する電源回路２２ａと、無線周波数（ＲＦ）回路２２ｂと、変調回路２２ｃと、復調回路２２ｄと、ＣＰＵ２２ｅとを有する。ＲＦ回路２２ｂには質問器用アンテナ１１と共振回路を構成するコンデンサ（図示せず）が設けられる。またメモリ２１はＣＰＵ２２ｅに接続され、タグ１７のＩＣチップ１９から読取った情報が記憶される。イヤホン２４の入力部は音声変換部２３の出力に接続され、イヤホン２４の出力部は視覚障害者の耳に装着される。またＲＦＩＤ質問器１３はイヤホン２４と一体的に設けられる。なお、質問器はイヤホンと一体的ではなく、ステッキに内蔵してもよいが、イヤホンとの一体化やステッキへの内蔵が難しければ、視覚障害者が所持するように構成してもよい。
【００２１】
一方、ＲＦＩＤタグ１７のＩＣチップ１９は電源回路１９ａと、無線周波数（ＲＦ）回路１９ｂと、変調回路１９ｃと、復調回路１９ｄと、ＣＰＵ１９ｅと、このＣＰＵ１９ｅに接続されタグ１７の埋設された場所の情報が記憶されるメモリ１９ｆとを有する（図３）。電源回路１９ａはコンデンサ（図示せず）を内蔵し、このコンデンサはタグ用アンテナ１８とともに共振回路を構成する。このコンデンサにはタグ用アンテナ１８が特定の周波数の電波（上記共振回路が共振する周波数）を受信したときにその相互誘導作用で生じる電力が充電される。電源回路１９ａはこの電力を整流し安定化してＣＰＵ１９ｅに供給し、ＩＣチップ１９を活性化する。メモリ１９ｆはＲＯＭ（read only memory）、ＲＡＭ（ramdom-access memory）及びＥＥＰＲＯＭ（electrically erasable programmable read only memory）を含み、ＣＰＵ１９ｅの制御の下で上記ＲＦＩＤ質問器１３からの電波のデータ通信による読出しコマンドに応じて記憶されたデータの読出しを行うように構成される。
【００２２】
このように構成された質問器用アンテナ１１の動作を説明する。
視覚障害者は質問器用アンテナ１１が内蔵されたステッキ１２を携帯しかつイヤホン２４を耳に装着して歩行する。駅のホームに到着してステッキ１２の先端をホームの乗車位置に埋設されたＲＦＩＤタグ１７のタグ用アンテナ１８に向けると、ＲＦＩＤ質問器１３は質問器用アンテナ１１からタグ用アンテナ１８に向けて２値化されたデジタル信号の質問信号を特定周波数の電波により送信する。質問器１３から発せられるデジタル信号は、図示しない信号発生器から発せられ変調回路２２ｃで変調を受け、ＲＦ回路２２ｂでこの変調した信号を増幅して質問器用アンテナ１１から送信される。この変調には例えばＡＳＫ（振幅変調）、ＦＳＫ（周波数変調）又はＰＳＫ（位相変調）が挙げられる。送信された質問信号の電波はタグ用アンテナ１８に受信される。
【００２３】
このときタグ用アンテナ１８と電源回路１９ａのコンデンサとにより構成される共振回路の共振の振幅が大きくなるので、このコンデンサには十分な量の電力が充電される、即ち質問器用アンテナ１１とタグ用アンテナ１８の相互誘導作用により十分な量の電力が電源回路１９ａのコンデンサに充電される。電源回路１９ａはこの電力を整流し安定化してＣＰＵ１９ｅに供給し、ＩＣチップ１９を活性化し、更にＲＦ回路１９ｂを介して復調回路１９ｄで元のデジタル信号の質問信号を再現させる。ＣＰＵ１９ｅはこの質問信号に基づいてメモリ１９ｆに書込まれていたその場所に関する情報を送信する。この情報の送信は２値化されたデータ信号をＩＣチップ１９の変調回路１９ｃで変調し、ＲＦ回路１９ｂで増幅してタグ用アンテナ１８から送出することにより行われる。送信されたデータは質問器用アンテナ１１が受信し、処理部２２がタグ１７からの情報をメモリ２１に記憶するとともに、音声変換部２３に出力するので、視覚障害者は音声変換部２３で音声に変換された上記情報をイヤホン２４を通して聞くことができ、そのホームに入線する電車が行先の駅を通る電車であるか否かを速やかに判断することができる。
【００２４】
また質問器用アンテナ１１の磁芯部材１４は従来の磁芯部材（一対のテーパ部１４ｂ，１４ｂの最も太い部分を直径とする柱状の磁芯部材）と比べて、細く形成されて軽いので、ステッキ１２の先端に内蔵しても、視覚障害者の携帯性を損うことはない。また上記磁芯部材１４を用いた質問器用アンテナ１１の作動距離は従来の磁芯部材を用いた質問器用アンテナの作動距離と略同一となるので、アンテナ特性が低下することもない。更に磁芯部材１４の柱状部１４ａで磁束の通過する断面が小さくなるため、コイル本体１６の巻数を増やす必要があるけれども、コイル本体１６は細い柱状部１４ａに巻回されるため、コイル本体１６の全長が短くなってその電気抵抗が小さくなるとともに、磁芯部材１４に巻回したコイル本体１６の外径を小さくできる。この結果、この磁芯部材１４を用いたアンテナ１１とコンデンサにより構成される共振回路のＱ値が大きくなって共振の幅が鋭くなるという利点がある。
【００２５】
図４及び図５は本発明の第１の実施の形態を示す。図４及び図５において図１及び図２と同一符号は同一部品を示す。
この実施の形態では、磁芯部材３４の一対のテーパ部１４ｂ，１４ｂに一対のテーパ穴３４ｃ，３４ｃがそれぞれ形成される。上記テーパ穴３４ｃ，３４ｃは磁芯部材３４の両端面から柱状部１４ａに向うに従って穴径がそれぞれ小さくなるように形成される。なお、上記テーパ穴は一対のテーパ部のいずれか一方に設けてもよい。上記以外は第１の参考の形態と同一に構成される。
このように構成された質問器用アンテナ３１では、磁芯部材３４が第１の参考の形態の磁芯部材より軽くなるので、携帯性が更に良好になるとともに、その磁芯部材３４を用いたアンテナ３１の作動距離は従来の柱状の磁芯部材を用いたアンテナの作動距離と略同一となる。上記以外の動作は第１の参考の形態の動作と略同様であるので、繰返しの説明を省略する。
【００２６】
図６及び図７は第２の参考の形態を示す。図６において図１と同一符号は同一部品を示す。
この参考の形態では、磁芯部材４４が磁性材料からなる粉末若しくはフレーク及びプラスチックの複合材により或いはフェライトにより、磁芯部材４４の軸線に沿って延びる通孔４４ａを有する筒状に形成される。上記以外は第１の参考の形態と同一に構成される。
このように構成された質問器用アンテナ４１では、磁芯部材４４の肉厚を十分に小さくすれば、磁芯部材４４が第１の参考の形態又は第１の実施の形態の磁芯部材より更に軽くなり、しかもその磁芯部材４４を用いた質問器用アンテナ４１の作動距離は第１の参考の形態又は第１の実施の形態の磁芯部材を用いた質問器用アンテナの作動距離と略同一となる。上記以外の動作は第１の参考の形態の動作と略同様であるので、繰返しの説明を省略する。
【００２７】
図８〜図１０は本発明の第２の実施の形態を示す。図８において図１と同一符号は同一部品を示す。
この実施の形態では、磁芯部材５４が、磁性材料からなる粉末若しくはフレーク及びプラスチックの複合材により或いはフェライトにより柱状に形成された柱状部５４ａと、柱状部５４ａの両端にそれぞれ接着されアモルファスの積層体或いはアモルファス箔及びプラスチックフィルムの積層体により形成された一対の積層部５４ｂ，５４ｂとを有する。柱状部５４ａは四角柱状に形成され、柱状部５４ａの両端には柱状部５４ａの両端から離れるに従って次第に太くなる一対の四角錐台５４ｃ，５４ｃが柱状部５４ａと同一材料で一体的に設けられる。また積層部５４ｂは柱状部５４ａより太い四角柱状に形成される、即ち柱状部５４ａの横断面積は一対の積層部５４ｂ，５４ｂの横断面積より小さく形成される。一対の積層部５４ｂ，５４ｂは一対の四角錐台５４ｃ，５４ｃの端面に接着剤を用いて接着される。更にアモルファス箔としてはＦｅ系（METGLAS2605S-2：アライドケミカル社製）やＣｏ系（METGLAS2714A：アライドケミカル社製）等を用いることが好ましく、プラスチックフィルムとしてはＰＥＴ（ポリエチレンテレフタレート）フィルム、ポリエチレンフィルム、ナイロンフィルム等を用いることが好ましい。上記以外は第１の参考の形態と同一に構成される。
【００２８】
このように構成された質問器用アンテナ５１では、磁芯部材５４の中央の柱状部５４ａが複合材により形成されているため、渦電流が発生せず、かつ高周波損失が少ない。この結果、上記磁芯部材５４を用いたアンテナ５１とコンデンサにより構成される共振回路のＱ値は低下しない。また比較的比重の大きな柱状部５４ａが細く形成されかつ比較的大径の一対の積層部５４ｂ，５４ｂの比重が小さいため、アンテナ５１全体の重量を低減できる。上記以外の動作は第１の参考の形態の動作と略同様であるので、繰返しの説明を省略する。
【００２９】
図１１及び図１２は第３の参考の形態を示す。図１１において図１と同一符号は同一部品を示す。
この参考の形態では、磁芯部材６４がアモルファスの積層体或いはアモルファス箔及びプラスチックフィルムの積層体により四角柱状に形成される。アモルファス箔としてはＦｅ系（METGLAS2605S-2：アライドケミカル社製）やＣｏ系（METGLAS2714A：アライドケミカル社製）等を用いることが好ましく、プラスチックフィルムとしてはＰＥＴ（ポリエチレンテレフタレート）フィルム、ポリエチレンフィルム、ナイロンフィルム等を用いることが好ましい。上記以外は第１の参考の形態と同一に構成される。
【００３０】
このように構成された質問器用アンテナ６１では、磁芯部材６４を比重の比較的小さいアモルファスの積層体或いはアモルファス箔及びプラスチックフィルムの積層体にて形成したので、磁芯部材６４を軽くすることができる。この場合、磁芯部材６４に渦電流が発生し易く、高周波損失が多くなるため、この磁芯部材６４を用いたアンテナ６１とコンデンサにより構成される共振回路のＱ値が低下する。しかし、Ｑ値が低くても作動するＩＣチップが存在するため、上記アンテナ６１はこのようなＩＣチップを用いたＲＦＩＤ用タグに適用できる。上記以外の動作は第１の参考の形態の動作と略同様であるので、繰返しの説明を省略する。
【００３１】
図１３〜図１５は本発明の第３の実施の形態を示す。
この実施の形態では、磁芯部材７４が四角柱状に形成された柱状部７４ａと、柱状部７４ａの一端に接続された四角柱状の積層部７４ｂとを有する。柱状部７４ａは第２の実施の形態の柱状部と同様に、磁性材料からなる粉末若しくはフレーク及びプラスチックの複合材により或いはフェライトによりして形成される。また積層部７４ｂは第２の実施の形態の積層部と同様に、アモルファス箔及びプラスチックフィルムの積層体により形成されるか、或いはアモルファス箔のみの積層体により形成される。柱状部７４ａの一端と積層部７４ｂの一端とは接着剤を用いて直接接続される。なお、柱状部の一端と積層部の一端とが接触するように、柱状部及び積層部を図示しないベース板に接着剤を用いて接着することにより、間接的に接続してもよい。またコイル本体１６は柱状部７４ａに巻回される。上記以外は第１の参考の形態と同一に構成される。
このように構成された質問器用アンテナ７１では、磁芯部材７４の積層部７４ｂを比重の比較的小さいアモルファス箔及びプラスチックフィルムの積層体にて形成すれば、磁芯部材７４をある程度軽くすることができる。また磁芯部材７４には上記第３の参考の形態の磁芯部材より渦電流が発生し難くかつ高周波損失が少なくなるため、この磁芯部材７４を用いたアンテナ７１とコンデンサにより構成される共振回路のＱ値は第３の参考の形態の磁芯部材を用いた共振回路のＱ値より高くなる。上記以外の動作は第１の参考の形態の動作と略同様であるので、繰返しの説明を省略する。
【００３２】
図１６〜図１８は本発明の第４の実施の形態を示す。
この実施の形態では、磁芯部材８４の積層部８４ｂの横断面積が柱状部７４ａの横断面積より小さく形成される。即ち、磁芯部材８４の柱状部７４ａは第３の実施の形態の柱状部と同一に形成され、積層部８４ｂは第３の実施の形態の積層部より厚さが薄く形成される。また磁芯部材８４は柱状部７４ａの他端がステッキ（図示せず）の先端に位置するようにステッキに内蔵される。柱状部７４ａの一端と積層部８４ｂの一端とは第３の実施の形態と同様に、接着剤を用いて直接或いは間接的に接続される。更にコイル本体１６は柱状部７４ａに巻回される。上記以外は第１の参考の形態と同一に構成される。
このように構成された質問器用アンテナ８１では、磁芯部材８４をステッキに内蔵するときに磁芯部材８４の向きが上述のように限定されるけれども、積層部８４ｂの横断面積が柱状部７４ａの横断面積より小さいため、積層部８４ｂに沿ってＲＦＩＤ質問器１３や電池等を収容するスペースを確保できる。この結果、このアンテナ８１を含むＲＦＩＤ質問器１３の構造が簡単になり、しかも小型化することができるの、ステッキの不使用時にステッキをコンパクトに折畳むことができる。上記以外の動作は第１の参考の形態の動作と略同様であるので、繰返しの説明を省略する。
【００３３】
図１９〜図２１は本発明の第５の実施の形態を示す。
この実施の形態では、磁芯部材９４の柱状部７４ａの一端に、一対の積層部９４ｂ，９４ｂが長手方向に直交する方向に所定のスペース９４ｃをあけた状態でそれぞれ接続される。即ち、磁芯部材９４の柱状部７４ａは第３の実施の形態の柱状部と同一に形成され、一対の積層部９４ｂ，９４ｂは第３の実施の形態の積層部より厚さが薄く形成される。またコイル本体１６は柱状部７４ａに巻回される。上記以外は第１の参考の形態と同一に構成される。
このように構成された質問器用アンテナ９１では、磁芯部材９４をステッキに内蔵するときに磁芯部材９４の向きが限定されず、一対の積層部９４ｂ，９４ｂの間のスペース９４ｃにＲＦＩＤ質問器１３や電池等を収容することができる。この結果、このアンテナ９１を含むＲＦＩＤ質問器１３の構造が簡単になり、しかも小型化することができるの、ステッキの不使用時にステッキをコンパクトに折畳むことができる。上記以外の動作は第１の参考の形態の動作と略同様であるので、繰返しの説明を省略する。
【００３４】
図２２〜図２４は本発明の第６の実施の形態を示す。
この実施の形態では、磁芯部材１０４が円柱状に形成された柱状部１０４ａと、柱状部１０４ａの一端に接続され円筒状に形成された積層部１０４ｂとを有する。柱状部１０４ａは磁性材料からなる粉末若しくはフレーク及びプラスチックの複合材により或いはフェライトにより形成され、積層部１０４ｂはアモルファス箔の積層体或いはアモルファス箔及びプラスチックフィルムの積層体により形成される。また柱状部１０４ａの一端には小径の突起１０４ｃが突設される。柱状部１０４ａの一端と積層部１０４ｂの一端とは柱状部１０４ａの突起１０４ｃを積層部１０４ｂの通孔１０４ｄに挿入した状態で接着剤を用いて直接接続される。またコイル本体１６は柱状部１０４ａに巻回される。更に積層部１０４ｂのアモルファス箔等の積層方向は積層作業の容易性から積層部１０４ｂの円周方向に積層される。なお、積層部のアモルファス箔等の積層方向を円周方向ではなく、水平方向又は鉛直方向に積層してもよい。上記以外は第１の参考の形態と同一に構成される。
このように構成された質問器用アンテナ１０１では、磁芯部材１０４をステッキに内蔵するときに磁芯部材１０４の向きが限定されず、積層部１０４ｂの通孔１０４ｄにＲＦＩＤ質問器１３や電池等を収容することができる。この結果、このアンテナ１０１を含むＲＦＩＤ質問器１３の構造が簡単になり、しかも小型化することができるの、ステッキの不使用時にステッキをコンパクトに折畳むことができる。上記以外の動作は第１の参考の形態の動作と略同様であるので、繰返しの説明を省略する。
【００３５】
図２５〜図２７は本発明の第７の実施の形態を示す。
この実施の形態では、磁芯部材１１４の柱状部１０４ａが第６の実施の形態の柱状部と同一に形成され、積層部１１４ｂが第６の実施の形態の積層部を縦に半分に割った半円筒状に形成される。柱状部１０４ａの一端と積層部１１４ｂの一端とは柱状部１０４ａの突起１０４ｃを積層部１１４ｂの凹部１１４ｄに挿入した状態で接着剤を用いて直接接続される。また磁芯部材１１４は柱状部１０４ａの他端がステッキの先端に位置するようにステッキに内蔵される。またコイル本体１６は柱状部１０４ａに巻回される。更に積層部１１４ｂのアモルファス箔等の積層方向は積層作業の容易性から積層部１１４ｂの円周方向に積層される。なお、積層部のアモルファス箔等の積層方向を円周方向ではなく、水平方向又は鉛直方向に積層してもよい。上記以外は第１の参考の形態と同一に構成される。
このように構成された質問器用アンテナ１１１では、磁芯部材１１４をステッキに内蔵するときに磁芯部材１１４の向きが上述のように限定されるけれども、積層部１１４ｂの横断面積が柱状部１０４ａの横断面積より小さいため、積層部１１４ｂに沿ってＲＦＩＤ質問器１３や電池等を収容するスペースを確保できる。この結果、このアンテナ１１１を含むＲＦＩＤ質問器１３の構造が簡単になり、しかも小型化することができるの、ステッキの不使用時にステッキをコンパクトに折畳むことができる。上記以外の動作は第１の参考の形態の動作と略同様であるので、繰返しの説明を省略する。
【００３６】
【実施例】
次に本発明の実施例を比較例及び参考例とともに詳しく説明する。
＜参考例１＞
９２重量％の鉄粉と８重量％のポリエチレンとの混練物を射出成形することにより、直径×長さが１０ｍｍ×６０ｍｍである円柱状の複合材製の磁芯部材を作製した。この磁芯部材は図１及び図２に示すように、直径×長さが７ｍｍ×３０ｍｍの円柱状に形成された柱状部１４ａと、最大外径×最小外径×長さがそれぞれ１０ｍｍ×７ｍｍ×１５ｍｍである一対のテーパ部１４ｂ，１４ｂを有する。この磁芯部材１４の柱状部１４ａ外周面に直径が０．１５ｍｍの被覆銅線を３９０回巻いてコイル本体１６を作製し、質問器用アンテナ１１を得た。このアンテナ１１を参考例１とした。
＜参考例２＞
フェライトにより実施例１の磁芯部材と同一形状の磁芯部材を作製した。この磁芯部材の柱状部外周面に直径が０．１５ｍｍの被覆銅線を３００回巻いてコイル本体を作製し、質問器用アンテナを得た。このアンテナを参考例２とした。
【００３７】
＜実施例１＞
磁芯部材を参考例１の磁芯部材と同一材料で同一形状に作製した後に、図４及び図５に示すように、一対のテーパ部１４ｂ，１４ｂ内に磁芯部材３４の両端面から柱状部１４ａに向うに従って穴径がそれぞれ小さくなる一対のテーパ穴３４ｃ，３４ｃを形成した。これらのテーパ穴３４ｃ，３４ｃの最大内径×長さはそれぞれ７ｍｍ×１５ｍｍであった。この磁芯部材３４の柱状部１４ａ外周面に直径が０．１５ｍｍの被覆銅線を４００回巻いてコイル本体１６を作製し、質問器用アンテナ３１を得た。このアンテナ３１を実施例１とした。
＜参考例３＞
図６及び図７に示すように、９２重量％の鉄粉と８重量％のポリエチレンとの混練物を射出成形することにより、外径×内径×長さが１０ｍｍ×７ｍｍ×６０ｍｍである円筒状の複合材製の磁芯部材を作製した。この磁芯部材４４の中央外周面に直径が０．１５ｍｍの被覆銅線を３９０回巻いてコイル本体１６を作製し、質問器用アンテナ４１を得た。このアンテナ４１を参考例３とした。
【００３８】
＜実施例２＞
９２重量％の鉄粉と８重量％のポリエチレンとの混練物を射出成形することにより、縦×横×長さが７ｍｍ×７ｍｍ×３０ｍｍである四角柱状の複合材製の柱状部５４ａを作製した（図８〜図１０）。一方、厚さ２５μｍのアモルファス箔（METGLAS2705A：アライドケミカル社製）と、厚さが０．２５ｍｍのＰＥＴ（ポリエチレンテレフタレート）フィルムとを交互に積層して縦×横×長さが１０ｍｍ×１０ｍｍ×１２ｍｍの一対の積層部５４ｂ，５４ｂをそれぞれ形成した。なお、柱状部５４ａの両端には、柱状部５４ａの両端から離れるに従って次第に太くなる一対の四角錐台５４ｃ，５４ｃを上記複合材により柱状部５４ａと一体的に形成した。一対の四角錐台５４ｃ，５４ｃの端面に一対の積層部５４ｂ，５４ｂを接着剤を用いて接着することにより磁芯部材５４を作製した。この磁芯部材５４の柱状部５４ａ外周面に直径が０．１５ｍｍの被覆銅線を３２０回巻いてコイル本体１６を作製し、質問器用アンテナ５１を得た。このアンテナ５１を実施例２とした。
＜実施例３＞
フェライトにより縦×横×長さが７ｍｍ×７ｍｍ×３０ｍｍの四角柱状の柱状部を作製した。また一対の積層部を実施例２の一対の積層部と同様にして作製した。なお、柱状部の両端には、柱状部の両端から離れるに従って次第に太くなる一対の四角錐台を上記フェライトにより柱状部と一体的に形成した。一対の四角錐台の端面に一対の積層部を接着剤を用いて接着することにより磁芯部材を作製した。この磁芯部材の柱状部外周面に直径が０．１５ｍｍの被覆銅線を３３０回巻いてコイル本体を作製し、質問器用アンテナを得た。このアンテナを実施例３とした。
【００３９】
＜参考例４＞
図１１及び図１２に示すように、厚さが２５μｍのアモルファス箔（METGLAS2705A：アライドケミカル社製）と、厚さが０．２５ｍｍのＰＥＴ（ポリエチレンテレフタレート）フィルムとを交互に積層して縦×横×長さが１０ｍｍ×１０ｍｍ×６０ｍｍの磁芯部材６４を形成した。この磁芯部材６４の中央外周面に直径が０．１５ｍｍの被覆銅線を２９０回巻いてコイル本体１６を作製し、質問器用アンテナ６１を得た。このアンテナ６１を参考例４とした。
＜実施例４＞
図１３〜図１５に示すように、フェライトにより縦×横×長さが７ｍｍ×７ｍｍ×３０ｍｍの四角柱状の柱状部７４ａを作製した。また厚さが２０μｍのアモルファス箔（METGLAS2705A：アライドケミカル社製）と、厚さが０．５ｍｍのＰＥＴ（ポリエチレンテレフタレート）フィルムとを交互に積層して縦×横×長さが１０ｍｍ×１０ｍｍ×３０ｍｍの四角柱状の積層部７４ｂを作製した。柱状部７４ａの一端と積層部７４ｂの一端とを接着剤を用いて接続することにより磁芯部材７４を得た。この磁芯部材７４の柱状部７４ａに直径が０．１５ｍｍの被覆銅線を２８０回巻いてコイル本体１６を作製し、質問器用アンテナ７１を得た。このアンテナ７１を実施例４とした。
【００４０】
＜実施例５＞
図１６〜図１８に示すように、９２重量％の鉄粉と８重量％のポリエチレンとの混練物を射出成形することにより、縦×横×長さが７ｍｍ×７ｍｍ×３０ｍｍである四角柱状の複合材製の柱状部７４ａを作製した。また厚さが２０μｍのアモルファス箔（METGLAS2705A：アライドケミカル社製）と、厚さが０．５ｍｍのＰＥＴ（ポリエチレンテレフタレート）フィルムとを交互に積層して縦×横×長さが１０ｍｍ×１０ｍｍ×３０ｍｍの四角柱状の積層部８４ｂを作製した。柱状部７４ａの一端と積層部８４ｂの一端とを接着剤を用いて接続することにより磁芯部材を得た。この磁芯部材８４の柱状部７４ａに直径が０．１５ｍｍの被覆銅線を２７０回巻いてコイル本体１６を作製し、質問器用アンテナ８１を得た。このアンテナ８１を実施例５とした。
＜実施例６＞
図１９〜図２１に示すように、９２重量％の鉄粉と８重量％のポリエチレンとの混練物を射出成形することにより、縦×横×長さが７ｍｍ×７ｍｍ×３０ｍｍである四角柱状の複合材製の柱状部７４ａを作製した。また厚さが２０μｍのアモルファス箔（METGLAS2705A：アライドケミカル社製）と、厚さが０．５ｍｍのＰＥＴ（ポリエチレンテレフタレート）フィルムとを交互に積層して縦×横×長さが１０ｍｍ×１．５ｍｍ×３０ｍｍの四角柱状の積層部９４ｂ，９４ｂを２本作製した。柱状部７４ａの一端に２本の積層部９４ｂ，９４ｂの一端を上下に所定の間隔をあけ接着剤を用いて接続することにより磁芯部材９４を得た。この磁芯部材９４の柱状部７４ａに直径が０．１５ｍｍの被覆銅線を３５０回巻いてコイル本体１６を作製し、質問器用アンテナ９１を得た。このアンテナ９１を実施例６とした。
【００４１】
＜実施例７＞
図２２〜図２４に示すように、９２重量％の鉄粉と８重量％のポリエチレンとの混練物を射出成形することにより、外径×長さが７ｍｍ×３０ｍｍである円柱状の複合材製の柱状部１０４ａを作製した。この柱状部１０４ａの一端には外径が６ｍｍの突起１０４ｃを突設した。また厚さが２０μｍのアモルファス箔（METGLAS2705A：アライドケミカル社製）と、厚さが０．１ｍｍのＰＥＴ（ポリエチレンテレフタレート）フィルムとを交互に積層して外径×内径×長さが７ｍｍ×６ｍｍ×３０ｍｍの円筒状の積層部１０４ｂを作製した。柱状部１０４ａの突起１０４ｃを積層部１０４ｂの一端から通孔１０４ｄに挿入し接着剤を用いて接続することにより磁芯部材１０４を得た。この磁芯部材１０４の柱状部１０４ａに直径が０．１５ｍｍの被覆銅線を３００回巻いてコイル本体１６を作製し、質問器用アンテナ１０１を得た。このアンテナ１０１を実施例７とした。
＜実施例８＞
図２５〜図２７に示すように、９２重量％の鉄粉と８重量％のポリエチレンとの混練物を射出成形することにより、外径×長さが７ｍｍ×３０ｍｍである円柱状の複合材製の柱状部１０４ａを作製した。この柱状部１０４ａの一端には外径が６ｍｍの突起１０４ｃを突設した。また厚さ２０μｍのアモルファス箔（METGLAS2705A：アライドケミカル社製）と、厚さが０．１ｍｍのＰＥＴ（ポリエチレンテレフタレート）フィルムとを交互に積層して外径×内径×長さが７ｍｍ×５ｍｍ×３０ｍｍの半円筒状の積層部１１４ｂを作製した。柱状部１０４ａの突起１０４ｃを積層部１１４ｂの一端から凹部１１４ｄに挿入し接着剤を用いて接続することにより磁芯部材１１４を得た。この磁芯部材１１４の柱状部１０４ａに直径が０．１５ｍｍの被覆銅線を３２０回巻いてコイル本体１６を作製し、質問器用アンテナ１１１を得た。このアンテナ１１１を実施例８とした。
【００４２】
＜比較例１＞
９２重量％の鉄粉と８重量％のポリエチレンとの混練物を射出成形することにより、直径×長さが１０ｍｍ×６０ｍｍである円柱状の複合材製の磁芯部材を作製した。この磁芯部材の中央外周面に直径が０．１５ｍｍの被覆銅線を３４０回巻いてコイル本体を作製し、質問器用アンテナを得た。このアンテナを比較例１とした。
【００４３】
＜比較試験１及び評価＞
実施例１〜８、参考例１〜４及び比較例１の質問器用アンテナのアンテナコイルの両端を質問器にそれぞれ接続し、これらのアンテナをＲＦＩＤ用タグ（タグ用アンテナとＩＣチップ（HT1 MOA2 S30：Philips Semiconductors社製）からなる。）のタグ用アンテナに次第に近付けていき、タグが作動したときの質問器用アンテナとタグ用アンテナとの距離をそれぞれ測定した。ここでＲＦＩＤ用タグはタグ用アンテナと、このアンテナに接続されたＩＣチップ（HT1 MOA2 S30：Philips Semiconductors社製）とを備える。またタグ用アンテナは比較例１の磁芯部材と同一材料で同一形状に形成された磁芯部材と、この磁芯部材の中央外周面に直径が０．１５ｍｍの被覆銅線を３４０回巻いて形成されたコイル本体とを有する。
また各質問器用アンテナの自己インダクタンスと、質問器用アンテナと質問器内のコンデンサとにより構成される共振回路のＱ値をＱメータを用いてそれぞれ測定した。なお、Ｑ値の測定は電波の周波数を０．１ＭＨｚ〜２０ＭＨｚの範囲で変化させて行った。これらの測定値を磁芯部材の材質及び重量とコイル本体の巻数とともに表１に示す。
【００４４】
【表１】

Figure 0004078807
【００４５】
表１から明らかなように、比較例１では重量が２３．５６ｇと比較的重い円柱状の磁芯部材を用いることにより、作動距離が６０ｃｍと比較的長く、かつＱ値が８５と比較的大きい質問器用アンテナを得ることができた。これに対して実施例１〜８及び参考例１〜３では、重量が１２．０２〜１５．３０ｇと比較例１の約半分の磁芯部材を用いても、作動距離及びＱ値が比較例１と略同等、即ち作動距離が５５〜６１ｃｍと比較的長く、Ｑ値が６９〜９３と比較的大きい質問器用アンテナを得ることができた。また参考例４ではＱ値が２５と小さいけれども、重量が比較例１の約４０％と極めて軽い磁芯部材を得ることができた。
【００４６】
【発明の効果】
以上述べたように、本発明によれば、磁芯部材の柱状部を磁性材料からなる粉末若しくはフレーク及びプラスチックの複合材により或いはフェライトにより柱状に形成し、この柱状部の両端に柱状部から離れるに従って次第に太くなる一対のテーパ部を設けたので、一対のテーパ部の最も太い部分を直径とする従来の柱状の磁芯部材と比べて、磁芯部材が軽くなり、しかもこの磁芯部材を用いたアンテナの作動距離は従来の磁芯部材を用いたアンテナの作動距離と略同一となる。この結果、本発明のアンテナを用いたＲＦＩＤ用タグは携帯性に優れたものとなる。また柱状部で磁束の通過する断面が小さくなるため、コイル本体の巻数を増やす必要があるけれども、コイル本体は細い柱状部に巻回されるため、コイル本体の全長が短くなってその電気抵抗が小さくなり、本発明のアンテナとコンデンサにより構成される共振回路のＱ値が大きくなって共振の幅が鋭くなる。
【００４７】
また一対のテーパ部のいずれか一方又は双方に、磁芯部材の端面から柱状部に向うに従って穴径が小さくなるテーパ穴を形成すれば、磁芯部材を更に軽くすることができるとともに、その磁芯部材を用いたアンテナの作動距離を従来の磁芯部材を用いたアンテナの作動距離と略同一にすることができる。
またコイル本体が巻回される柱状部を磁性材料からなる粉末若しくはフレーク及びプラスチックの複合材により或いはフェライトにより柱状に形成し、アモルファスの積層体或いはアモルファス箔及びプラスチックフィルムの積層体により形成された一対の積層部を上記柱状部の両端にそれぞれ接着すれば、磁芯部材の中央の柱状部で渦電流が発生しないため、高周波損失は少なく、この磁芯部材を用いたアンテナとコンデンサにより構成される共振回路のＱ値は低下しない。また一対の積層部は軽量であるため、アンテナ全体の重量を低減できる。
【００４８】
また比較的比重の大きな柱状部の横断面積を比較的比重の小さな一対の積層部の横断面積より小さく形成すれば、アンテナ全体の重量を更に低減できる。また柱状部で磁束の通過する断面が小さくなるため、コイル本体の巻数を増やす必要があるけれども、コイル本体は細い柱状部に巻回されるため、コイル本体の全長が短くなってその電気抵抗が小さくなり、この磁芯部材を用いたアンテナとコンデンサにより構成される共振回路のＱ値が大きくなって共振の幅が鋭くなる。
【００４９】
また磁芯部材の柱状部をフェライト等により柱状に形成し、アモルファス箔の積層体等により柱状に形成された積層部を柱状部の一端に接続すれば、この磁芯部材には上記磁芯部材より渦電流が発生し難くかつ高周波損失が少なくなるため、この磁芯部材を用いたアンテナとコンデンサにより構成される共振回路のＱ値は上記磁芯部材を用いた共振回路のＱ値より高くなる。
また積層部の横断面積を柱状部の横断面積より小さく形成すれば、積層部の横断面積が柱状部の横断面積より小さいため、積層部に沿って電子部品や電池等を収容するスペースを確保できる。この結果、アンテナを含むＲＦＩＤ質問器等の構造が簡単になり、しかも上記磁芯部材を用いたアンテナを小型化することができる。
また積層部にその長手方向に延びるスリットを形成すれば、積層部のスリットに電子部品や電池等を収容することができる。この結果、上記と同様の効果が得られる。
【００５０】
また磁芯部材の柱状部をフェライト等により柱状に形成し、アモルファス箔の積層体等により筒状に形成された積層部を柱状部の一端に接続すれば、積層部の通孔に電子部品や電池等を収容することができる。この結果、上記と同様の効果が得られる。
更に磁芯部材の柱状部をフェライト等により柱状に形成し、アモルファス箔の積層体等により半筒状に形成された積層部を柱状部の一端に接続すれば、積層部の横断面積が柱状部の横断面積より小さいため、積層部に沿って電子部品や電池等を収容するスペースを確保できる。この結果、上記と同様の効果が得られる。
【図面の簡単な説明】
【図１】 第１参考形態のＲＦＩＤ質問器の質問器用アンテナを示す要部破断側面図。
【図２】 図１のＡ矢視図。
【図３】 質問器用アンテナをタグ用アンテナに対向させた状態を示すＲＦＩＤ質問器及びＲＦＩＤタグの構成図。
【図４】 本発明の第１実施形態を示す図１に対応する要部破断側面図。
【図５】 図４のＢ矢視図。
【図６】 第２参考形態を示す図１に対応する要部破断側面図。
【図７】 図６のＣ−Ｃ線断面図。
【図８】 本発明の第２実施形態を示す図１に対応する要部破断側面図。
【図９】 図８のＤ矢視図。
【図１０】 そのアンテナの斜視図。
【図１１】 第３参考形態を示す図１に対応する要部破断側面図。
【図１２】 図１１のＥ−Ｅ線断面図。
【図１３】 本発明の第３実施形態を示す磁芯部材の縦断面図。
【図１４】 図１３のＦ−Ｆ線断面図。
【図１５】 図１３のＧ−Ｇ線断面図。
【図１６】 本発明の第４実施形態を示す磁芯部材の縦断面図。
【図１７】 図１６のＨ−Ｈ線断面図。
【図１８】 図１６のＩ−Ｉ線断面図。
【図１９】 本発明の第５実施形態を示す磁芯部材の縦断面図。
【図２０】 図１９のＪ−Ｊ線断面図。
【図２１】 図１９のＫ−Ｋ線断面図。
【図２２】 本発明の第６実施形態を示す磁芯部材の縦断面図。
【図２３】 図２２のＬ−Ｌ線断面図。
【図２４】 図２２のＭ−Ｍ線断面図。
【図２５】 本発明の第７実施形態を示す磁芯部材の縦断面図。
【図２６】 図２５のＮ−Ｎ線断面図。
【図２７】 図２５のＰ−Ｐ線断面図。
【符号の説明】
１１，３１，４１，５１，６１，７１，８１，９１，１０１，１１１ 質問器用アンテナ（ＲＦＩＤ用アンテナ）
１４，３４，４４，５４，６４，７４，８４，９４，１０４，１１４ 磁芯部材
１４ａ，５４ａ，７４ａ，１０４ａ 柱状部
１４ｂ テーパ部
１６ コイル本体
３４ｃ テーパ穴
４４ａ 通孔
５４ｂ，７４ｂ，８４ｂ，９４ｂ，１０４ｂ，１１４ｂ 積層部
９４ｃ スリット[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an antenna used for a tag using RFID (Radio Frequency Identification) technology and an interrogator for reading information stored in the tag.
[0002]
[Prior art]
Conventionally, RFID tags to which destination information such as buses is input are attached to buses, etc., RFID tags to which timetable information is input are embedded in the base of a time display board of a landing, and guidance information to a landing such as a bus is provided. Traffic using a non-contact recognition label in which the input RFID tag is embedded in the Braille guidance tile of the walking path, and the interrogator reads the information transmitted by each RFID tag via a cane-shaped antenna An information recognition device is disclosed (Japanese Patent Laid-Open No. 11-143418).
In the traffic information recognition device using the non-contact recognition label configured as described above, when a visually handicapped person walks on a Braille guidance tile on a walking path, guidance information transmitted from an RFID tag embedded in the tile is used as an antenna. Therefore, visually impaired persons can know the route to the bus stop without fail. When the staff arrives at the bus landing and directs the cane antenna toward the base of the time display board, the timetable information transmitted from the RFID tag embedded in the base is obtained by the interrogator via the antenna. Furthermore, when the cane antenna is pointed at the bus when it arrives at the landing, the destination information transmitted by the RFID tag attached to the bus can be obtained by the interrogator via the antenna. You can know if there is. In this way, visually impaired people can automatically get directions to transportation platforms, timetable information, etc., so they can go to their destinations smoothly without making a mistake on the roads and transportation. .
[0003]
[Problems to be solved by the invention]
However, in the traffic information recognition apparatus using the non-contact recognition label disclosed in the conventional Japanese Patent Application Laid-Open No. 11-143418, ferrite or the like is used to increase the working distance of the cane-shaped antenna connected to the interrogator. It is necessary to increase either or both of the diameter and length of the magnetic core member that is formed and the coil is wound, and when this magnetic core member is enlarged, the cane-like antenna becomes heavy and portability is increased. There was a bug that damaged.
An object of the present invention is to provide an RFID antenna that is lightweight, has a long working distance, and is excellent in portability.
Another object of the present invention is to provide an RFID antenna that has a simple structure and can be miniaturized by securing a space that can accommodate an electronic component, a battery, or the like in a magnetic core member.
[0004]
[Means for Solving the Problems]
As a result of repeating theoretical considerations and experiments, the present inventors have found that the RFID tag working distance (the distance between the RFID interrogator antenna and the RFID tag antenna, and the maximum distance at which the RFID tag can operate) is RFID. It has been found that the length of the magnetic core member of the interrogator or RFID tag antenna and the shape of the outer periphery of both ends thereof hardly change unless the shape and size of the outer periphery thereof are changed. That is, if the magnetic core member is not a column with a constant cross-sectional area, the length and the outer circumference of both ends are the same, the center is formed narrow, a pair of holes are formed near both ends, or the entire length is a through hole. It was found that the working distance hardly changed even when formed, and the present invention was made.
[0005]
Further, the inventors of the present invention have determined that the length of the antenna of the RFID interrogator or the magnetic core member of the RFID tag antenna is set so that one end of the RFID interrogator antenna always faces one end of the RFID tag antenna. It has been found that the working distance of the RFID tag hardly changes unless the shape of the outer circumference of the one end changes. That is, if the magnetic core member is not a column with a constant cross-sectional area, and the length and the outer circumference of one end are the same, the above working distance can be achieved even if the other end side is formed thin or a slit or hole is formed on the other end side. Was found to hardly change, and the present invention was made.
[0006]
The invention according to claim 1FIG.As shown in34This is an improvement of the RFID antenna formed by winding the coil body 16 around the antenna.
  Its characteristic configuration is a magnetic core member34Are formed of a magnetic material powder or flake and plastic composite material, or a columnar portion 14a around which the coil body 16 is wound, and is gradually formed as the distance from the columnar portion 14a increases. A pair of taper portions 14b, 14b,The taper holes 34c, 34c formed on one or both of the pair of taper portions 14b, 14b and having a hole diameter that decreases from the end surface of the magnetic core member 34 toward the columnar portion 14a;It is in having.
[0007]
  In the RFID antenna according to the first aspect, the magnetic core member 14 of the present invention has both ends from the center as compared with the conventional columnar magnetic core member having the diameter of the thickest portion of the pair of taper portions 14b and 14b. Narrower than conventional magnetic core members up to the vicinityIn addition, tapered holes 34c and 34c are formed in one or both of the pair of tapered portions 14b and 14b.Therefore, the working distance of the antenna 11 using the magnetic core member 14 is light and substantially the same as the working distance of the antenna using the conventional magnetic core member. Further, since the cross section through which the magnetic flux passes is reduced at the columnar portion 14a of the magnetic core member 14, it is necessary to increase the number of turns of the coil main body 16, but the coil main body 16 is wound around the thin columnar portion 14a. And the electrical resistance is reduced, the Q value of the resonance circuit constituted by the antenna 11 and the capacitor using the magnetic core member 14 is increased, and the resonance width is sharpened.
  Here, the Q value is defined as ωL / r, where ω is the angular frequency of the radio wave, r is the resistance value of the resonance circuit composed of the antenna and the capacitor, and L is the self-inductance of the coil body. It is known that the higher the Q value, the smaller the loss due to eddy currents, and the sharper the resonance.
[0010]
  Claim28, the magnetic core member 54 is formed of a magnetic material powder or flake and plastic composite material, or a columnar portion 54a around which the coil body 16 is wound. And a pair of laminated portions 54b and 54b formed by an amorphous laminated body or a laminated body of an amorphous foil and a plastic film, which are respectively bonded to both ends of the columnar portion 54a.
  This claim2In the RFID antenna described in 1), since no eddy current is generated in the central columnar portion 54a of the magnetic core member 54, there is little high-frequency loss, and a resonance circuit including the antenna 51 using the magnetic core member 54 and a capacitor is provided. The Q value does not decrease. Further, since the pair of laminated portions 54b and 54b is lightweight, the weight of the entire antenna 51 can be reduced.
[0011]
  Claim3The invention according to claim2Further, as shown in FIG. 8, the cross-sectional area of the columnar portion 54a is smaller than the cross-sectional area of the pair of laminated portions 54b and 54b.
  This claim3In the RFID antenna described in the above, the weight of the entire antenna 51 is further reduced by forming the columnar portion 54a having a relatively large specific gravity thin and reducing the specific gravity of the pair of relatively large diameter laminated portions 54b and 54b. it can. Further, since the cross section through which the magnetic flux passes is reduced at the columnar portion 54a, it is necessary to increase the number of turns of the coil body 16. However, since the coil body 16 is wound around the thin columnar portion 54a, the entire length of the coil body 16 is shortened. As a result, the electrical resistance is reduced, the Q value of the resonance circuit constituted by the antenna 51 and the capacitor using the magnetic core member 54 is increased, and the resonance width is sharpened.
[0013]
  Claim4In the invention according to FIG. 13, a magnetic core member 74 is formed of a magnetic material powder or flake and plastic composite material or a columnar portion 74a formed of ferrite with a columnar shape, and one end of the columnar portion 74a. And a laminated portion 74b formed in a columnar shape by a laminated body of amorphous foil or a laminated body of amorphous foil and plastic film.Then, the laminated portion 74b is directly connected to one end of the columnar portion 74a using an adhesive, or the columnar portion 74a and the laminated portion 74b are bonded to the base plate using an adhesive to be attached to one end of the columnar portion 74a. Indirectly connectedIt is characterized by that.
  This claim4In the RFID antenna described in 1), the magnetic core member 74 can be lightened to some extent if the laminated portion 74b of the magnetic core member 74 is formed of a laminated body of amorphous foil and plastic film having a relatively small specific gravity. Further, since the eddy current is less likely to occur in the magnetic core member 74 and the high-frequency loss is less than that in the magnetic core member of the sixth aspect, the Q of the resonance circuit constituted by the antenna 71 and the capacitor using the magnetic core member 74 is reduced. The value is higher than the Q value of the resonance circuit using the magnetic core member of claim 6.
[0014]
  Claim5The invention according to claim4Further, as shown in FIG. 16, the cross-sectional area of the laminated portion 84b is smaller than the cross-sectional area of the columnar portion 74a.
  This claim5In the RFID antenna described in (1), since the cross-sectional area of the laminated portion 84b is smaller than the cross-sectional area of the columnar portion 74a, a space for accommodating electronic components, batteries, and the like can be secured along the laminated portion 84b.
[0015]
  Claim6The invention according to claim4Further, as shown in FIG.,productlayerOf the columnar portion 74a at one end of the columnar portion 74a.A state in which a predetermined space 94c is opened in a direction orthogonal to the longitudinal directionDesoEach connectedA pair of stacked portions 94b and 94b.It is characterized by that.
  This claim6In the RFID antenna described in 1), an electronic component, a battery, or the like can be accommodated in a predetermined space 94c between the pair of stacked portions 94b and 94b. Further, since the outer periphery of the laminated portions 94b and 94b is the same as the laminated portion in which the space 94c is filled with an amorphous foil laminate or the like, the performance of the magnetic core member 94 is hardly changed.
[0016]
  Claim7In the invention according to FIG. 22, a magnetic core member 104 is formed of a magnetic material powder or flake and plastic composite material or a columnar portion 104a formed of ferrite with a columnar shape, and one end of the columnar portion 104a.Directly using glueAnd a laminated portion 104b formed in a cylindrical shape by a laminated body of amorphous foils or a laminated body of amorphous foils and a plastic film.
  This claim7In the RFID antenna described in 1), an electronic component, a battery, or the like can be accommodated in the cylindrical laminated portion 104.
[0017]
  Claim8In the invention according to FIG. 25, as shown in FIG. 25, a magnetic core member 114 is formed of a magnetic material powder or flake and plastic composite material, or a columnar portion 104a formed of ferrite with a columnar shape, and one end of the columnar portion 104a.Directly using glueAnd a laminated part 114b formed in a semi-cylindrical shape by a laminated body of amorphous foils or a laminated body of amorphous foils and a plastic film.
  This claim8In the RFID antenna described in 1), since the cross-sectional area of the laminated portion 114b is smaller than the cross-sectional area of the columnar portion 104a, a space for accommodating electronic components, batteries, and the like can be secured along the laminated portion 114b.
[0018]
  NextSecond1'sreferenceThe embodiment will be described with reference to the drawings.
  As shown in FIGS.This reference formThe RFID antenna 11 is an interrogator antenna built in the tip of a walking stick 12 carried by a visually impaired person and connected to an RFID interrogator 13. The antenna 11 includes a magnetic core member 14 and a coil body 16 wound around the magnetic core member 14. The RFID interrogator 13 is configured to read information stored in the memory 19f of the IC chip 19 of the RFID tag 17 via the interrogator antenna 11 (FIG. 3). The RFID tag 17 is buried at the boarding position of the platform of the station, buried at the top or bottom of the station stairs, buried at the bus stop, near the entrance of the amusement park ticket office or each amusement facility. It is buried, or it is buried near the ticket office such as a music hall or near each seat. Information on the place where the tag 17 is embedded (information unique to the tag 17) is stored in the memory 19f of the IC chip 19 of the tag 17, and the tag antenna 18 is electrically connected to the IC chip 19.
[0019]
The magnetic core member 14 of the interrogator antenna 11 has a columnar portion 14a formed in a columnar shape, and a pair of tapered portions 14b and 14b provided at both ends of the columnar portion 14a (FIGS. 1 and 2). The tapered portion 14b is formed so as to gradually become thicker as the distance from the columnar portion 14a increases. The magnetic core member 14a is formed of a composite material of metal or ferrite powder or flakes and plastic. Examples of the metal powder include carbonyl iron powder, atomized powder such as iron or permalloy, and reduced iron powder. In addition, as metal flakes, flakes obtained by mechanically flattening the above metal powder with a ball mill, roller, etc., amorphous flakes obtained by colliding molten iron or cobalt alloy with water-cooled copper, etc. Is used. Further, as the plastic, a thermoplastic plastic having good processability can be used, or a thermosetting plastic having good heat resistance can be used. The columnar portion 14a may be formed in a prismatic shape instead of a cylindrical shape.
[0020]
The RFID interrogator 13 transmits a radio wave carrying a predetermined interrogation signal from the interrogator antenna 11 and receives a radio wave carrying information specific to the tag 17 transmitted from the tag antenna 18 and stores it in the memory 21. And an audio conversion unit 23 for converting the information stored in the memory 21 into an audio signal, and an earphone 24 for converting the audio signal into audio (FIG. 3). The processing unit 22 includes a power supply circuit 22a that is connected to the interrogator antenna 11 and incorporates a battery (not shown), a radio frequency (RF) circuit 22b, a modulation circuit 22c, a demodulation circuit 22d, and a CPU 22e. The RF circuit 22b is provided with an interrogator antenna 11 and a capacitor (not shown) constituting a resonance circuit. The memory 21 is connected to the CPU 22e and stores information read from the IC chip 19 of the tag 17. The input part of the earphone 24 is connected to the output of the sound conversion part 23, and the output part of the earphone 24 is attached to the ear of a visually impaired person. The RFID interrogator 13 is provided integrally with the earphone 24. The interrogator is not integral with the earphone and may be built in the walking stick. However, if it is difficult to integrate with the earphone or built into the walking stick, the interrogator may be configured to be held by a visually impaired person.
[0021]
On the other hand, the IC chip 19 of the RFID tag 17 includes a power supply circuit 19a, a radio frequency (RF) circuit 19b, a modulation circuit 19c, a demodulation circuit 19d, a CPU 19e, and a place where the tag 17 is embedded in the CPU 19e. And a memory 19f for storing information (FIG. 3). The power supply circuit 19 a includes a capacitor (not shown), and this capacitor constitutes a resonance circuit together with the tag antenna 18. This capacitor is charged with electric power generated by mutual induction when the tag antenna 18 receives radio waves of a specific frequency (frequency at which the resonance circuit resonates). The power supply circuit 19a rectifies and stabilizes this power, supplies it to the CPU 19e, and activates the IC chip 19. The memory 19f includes a ROM (read only memory), a RAM (ramdom-access memory), and an EEPROM (electrically erasable programmable read only memory), and a read command based on radio wave data communication from the RFID interrogator 13 under the control of the CPU 19e. The stored data is read out in response to the above.
[0022]
The operation of the interrogator antenna 11 configured as described above will be described.
The visually handicapped person walks with carrying the walking stick 12 with the interrogator antenna 11 and wearing the earphone 24 on the ear. When arriving at the platform of the station and pointing the tip of the stick 12 toward the tag antenna 18 of the RFID tag 17 embedded at the boarding position of the platform, the RFID interrogator 13 is moved from the interrogator antenna 11 toward the tag antenna 18. A digitalized question signal is transmitted by radio waves of a specific frequency. The digital signal emitted from the interrogator 13 is emitted from a signal generator (not shown), modulated by the modulation circuit 22c, amplified by the RF circuit 22b, and transmitted from the interrogator antenna 11. Examples of this modulation include ASK (amplitude modulation), FSK (frequency modulation), and PSK (phase modulation). The transmitted radio wave of the interrogation signal is received by the tag antenna 18.
[0023]
At this time, since the resonance amplitude of the resonance circuit constituted by the tag antenna 18 and the capacitor of the power supply circuit 19a becomes large, this capacitor is charged with a sufficient amount of power, that is, the interrogator antenna 11 and the tag antenna. A sufficient amount of power is charged in the capacitor of the power supply circuit 19a by the mutual induction effect of the antenna 18. The power supply circuit 19a rectifies and stabilizes this power, supplies it to the CPU 19e, activates the IC chip 19, and further reproduces the interrogation signal of the original digital signal by the demodulation circuit 19d via the RF circuit 19b. The CPU 19e transmits information on the location written in the memory 19f based on the question signal. This information is transmitted by modulating the binarized data signal by the modulation circuit 19c of the IC chip 19, amplifying it by the RF circuit 19b, and transmitting it from the tag antenna 18. The transmitted data is received by the interrogator antenna 11, and the processing unit 22 stores the information from the tag 17 in the memory 21 and outputs it to the voice conversion unit 23. The converted information can be heard through the earphone 24, and it can be quickly determined whether or not the train entering the platform is a train passing through the destination station.
[0024]
Further, the magnetic core member 14 of the interrogator antenna 11 is thinner and lighter than a conventional magnetic core member (a columnar magnetic core member having the diameter of the thickest part of the pair of taper portions 14b and 14b). Even if it is built in the tip of 12, it will not impair the portability of the visually impaired. Further, since the working distance of the interrogator antenna 11 using the magnetic core member 14 is substantially the same as the working distance of the conventional interrogator antenna using the magnetic core member, the antenna characteristics are not deteriorated. Further, since the cross section through which the magnetic flux passes is reduced at the columnar portion 14a of the magnetic core member 14, it is necessary to increase the number of turns of the coil main body 16, but the coil main body 16 is wound around the thin columnar portion 14a. The overall length of the coil body is shortened to reduce its electrical resistance, and the outer diameter of the coil body 16 wound around the magnetic core member 14 can be reduced. As a result, there is an advantage that a resonance circuit constituted by the antenna 11 and the capacitor using the magnetic core member 14 has a large Q value and a sharp resonance.
[0025]
  4 and 5 show the present invention.FirstAn embodiment of the present invention will be described. 4 and 5, the same reference numerals as those in FIGS. 1 and 2 denote the same components.
  In this embodiment, a pair of tapered holes 34c, 34c are formed in the pair of tapered portions 14b, 14b of the magnetic core member 34, respectively. The tapered holes 34c and 34c are formed so that the hole diameters become smaller from the both end surfaces of the magnetic core member 34 toward the columnar portion 14a. The tapered hole may be provided in either one of the pair of tapered portions. 1st other than the abovereferenceThe configuration is the same as that.
  In the interrogator antenna 31 configured as described above, the magnetic core member 34 has the first structure.referenceTherefore, the portability is further improved, and the working distance of the antenna 31 using the magnetic core member 34 is substantially the same as the working distance of the antenna using the conventional columnar magnetic core member. It will be the same. Operation other than the above is the firstreferenceSince the operation is substantially the same as that of the embodiment, repeated description is omitted.
[0026]
  6 and 7 areSecond referenceThe form of is shown. 6, the same reference numerals as those in FIG. 1 denote the same components.
  thisreferenceIn this embodiment, the magnetic core member 44 is formed in a cylindrical shape having a through hole 44 a extending along the axis of the magnetic core member 44 by a composite material of powder or flakes made of a magnetic material and plastic, or by ferrite. 1st other than the abovereferenceThe configuration is the same as that.
  In the interrogator antenna 41 configured as described above, if the thickness of the magnetic core member 44 is made sufficiently small, the magnetic core member 44 becomes the first one.Reference formOrFirstThe working distance of the interrogator antenna 41 using the magnetic core member 44 is further lighter than that of the magnetic core member of the first embodiment.Reference formOrFirstIt becomes substantially the same as the working distance of the interrogator antenna using the magnetic core member of the embodiment. Operation other than the above is the firstreferenceSince the operation is substantially the same as that of the embodiment, repeated description is omitted.
[0027]
  8 to 10 show the present invention.SecondAn embodiment of the present invention will be described. 8, the same reference numerals as those in FIG. 1 denote the same parts.
  In this embodiment, the magnetic core member 54 is formed of a magnetic material powder or flake and plastic composite material or a columnar portion 54a formed in a columnar shape with ferrite, and an amorphous laminate bonded to both ends of the columnar portion 54a. Or a pair of laminated portions 54b, 54b formed of a laminate of a body or an amorphous foil and a plastic film. The columnar portion 54a is formed in a square columnar shape, and a pair of square frustums 54c and 54c that gradually increase in thickness as the distance from the both ends of the columnar portion 54a is integrally provided at both ends of the columnar portion 54a with the same material as the columnar portion 54a. The stacked portion 54b is formed in a rectangular column shape thicker than the columnar portion 54a, that is, the cross-sectional area of the columnar portion 54a is formed smaller than the cross-sectional area of the pair of stacked portions 54b and 54b. The pair of stacked portions 54b and 54b are bonded to the end surfaces of the pair of square frustums 54c and 54c using an adhesive. Further, it is preferable to use Fe-based (METGLAS2605S-2: manufactured by Allied Chemical Co.) or Co-based (METGLAS2714A: manufactured by Allied Chemical Co.) as an amorphous foil, and PET (polyethylene terephthalate) film, polyethylene film, nylon as a plastic film. It is preferable to use a film or the like. 1st other than the abovereferenceThe configuration is the same as that.
[0028]
  In the interrogator antenna 51 configured as described above, since the central columnar portion 54a of the magnetic core member 54 is formed of a composite material, eddy current does not occur and high-frequency loss is small. As a result, the Q value of the resonance circuit including the antenna 51 and the capacitor using the magnetic core member 54 does not decrease. Further, since the columnar portion 54a having a relatively large specific gravity is formed thin and the specific gravity of the pair of relatively large diameter laminated portions 54b and 54b is small, the weight of the entire antenna 51 can be reduced. Operation other than the above is the firstreferenceSince the operation is substantially the same as that of the embodiment, repeated description is omitted.
[0029]
  11 and 12 areThird referenceThe form of is shown. 11, the same reference numerals as those in FIG. 1 denote the same components.
  thisreferenceIn this embodiment, the magnetic core member 64 is formed in a quadrangular prism shape from an amorphous laminate or a laminate of an amorphous foil and a plastic film. It is preferable to use an Fe-based (METGLAS2605S-2: Allied Chemical Co.) or Co-based (METGLAS2714A: Allied Chemical Co.) as the amorphous foil, and PET (polyethylene terephthalate) film, polyethylene film, nylon film as the plastic film. Etc. are preferably used. 1st other than the abovereferenceThe configuration is the same as that.
[0030]
  In the interrogator antenna 61 configured as described above, the magnetic core member 64 is formed of an amorphous laminate having a relatively small specific gravity or a laminate of an amorphous foil and a plastic film. it can. In this case, an eddy current is likely to be generated in the magnetic core member 64 and the high-frequency loss is increased. Therefore, the Q value of the resonance circuit including the antenna 61 and the capacitor using the magnetic core member 64 is lowered. However, since there is an IC chip that operates even when the Q value is low, the antenna 61 can be applied to an RFID tag using such an IC chip. Operation other than the above is the firstreferenceSince the operation is substantially the same as that of the embodiment, repeated description is omitted.
[0031]
  13 to 15 show the present invention.ThirdImplementationofThe form is shown.
  In this embodiment, the magnetic core member 74 has a columnar portion 74a formed in a quadrangular column shape, and a quadrangular columnar stacked portion 74b connected to one end of the columnar portion 74a. The columnar portion 74a isSecondSimilarly to the columnar portion of the embodiment, it is formed by a composite material of powder or flakes made of a magnetic material and plastic, or by ferrite. The laminated portion 74b isSecondSimilarly to the laminated portion of the embodiment, it is formed by a laminated body of an amorphous foil and a plastic film, or is formed by a laminated body of only an amorphous foil. One end of the columnar portion 74a and one end of the stacked portion 74b are directly connected using an adhesive. In addition, you may connect indirectly by adhere | attaching a columnar part and a laminated part to the base board which is not shown in figure so that the end of a columnar part and the one end of a laminated part may contact. The coil body 16 is wound around the columnar portion 74a. 1st other than the abovereferenceThe configuration is the same as that.
  In the interrogator antenna 71 configured as described above, the magnetic core member 74 can be lightened to some extent if the laminated portion 74b of the magnetic core member 74 is formed of a laminated body of amorphous foil and plastic film having a relatively low specific gravity. it can. The magnetic core member 74 has the above-mentionedThirdofreferenceSince the eddy current is less likely to occur and the high-frequency loss is less than that of the magnetic core member of the form of FIG.ThirdofreferenceThe Q value of the resonance circuit using the magnetic core member of the form is higher. Operation other than the above is the firstreferenceSince the operation is substantially the same as that of the embodiment, repeated description is omitted.
[0032]
  16 to 18 show the present invention.4thImplementationofThe form is shown.
  In this embodiment, the cross-sectional area of the laminated portion 84b of the magnetic core member 84 is formed smaller than the cross-sectional area of the columnar portion 74a. That is, the columnar portion 74a of the magnetic core member 84 isThirdThe same as the columnar portion of the embodiment, the laminated portion 84bThirdThe thickness is smaller than that of the laminated portion of the embodiment. The magnetic core member 84 is built into the stick so that the other end of the columnar portion 74a is positioned at the tip of the stick (not shown). One end of the columnar portion 74a and one end of the laminated portion 84bThirdAs in the first embodiment, it is directly or indirectly connected using an adhesive. Further, the coil body 16 is wound around the columnar portion 74a. 1st other than the abovereferenceThe configuration is the same as that.
  In the interrogator antenna 81 configured as described above, the orientation of the magnetic core member 84 is limited as described above when the magnetic core member 84 is built in the stick, but the cross-sectional area of the stacked portion 84b is that of the columnar portion 74a. Since it is smaller than the cross-sectional area, it is possible to secure a space for accommodating the RFID interrogator 13 and the battery along the stacked portion 84b. As a result, the structure of the RFID interrogator 13 including the antenna 81 can be simplified and the size can be reduced, and the stick can be folded compactly when the stick is not used. Operation other than the above is the firstreferenceSince the operation is substantially the same as that of the embodiment, repeated description is omitted.
[0033]
  19 to 21 show the present invention.5thImplementationofThe form is shown.
  In this embodiment, a pair of laminated portions 94b and 94b are connected to one end of the columnar portion 74a of the magnetic core member 94 in a state where a predetermined space 94c is opened in a direction orthogonal to the longitudinal direction. That is, the columnar portion 74a of the magnetic core member 94 isThirdThe same as the columnar part of the embodiment, the pair of laminated parts 94b, 94bThirdThe thickness is smaller than that of the laminated portion of the embodiment. The coil body 16 is wound around the columnar portion 74a. 1st other than the abovereferenceThe configuration is the same as that.
  In the interrogator antenna 91 configured as described above, the orientation of the magnetic core member 94 is not limited when the magnetic core member 94 is built in the stick, and the RFID interrogator is placed in the space 94c between the pair of laminated portions 94b and 94b. 13 or a battery can be accommodated. As a result, the structure of the RFID interrogator 13 including the antenna 91 can be simplified and the size can be reduced, and the stick can be folded compactly when the stick is not used. Operation other than the above is the firstreferenceSince the operation is substantially the same as that of the embodiment, repeated description is omitted.
[0034]
  22 to 24 show the present invention.6thImplementationofThe form is shown.
  In this embodiment, the magnetic core member 104 has a columnar portion 104a formed in a columnar shape, and a stacked portion 104b connected to one end of the columnar portion 104a and formed in a cylindrical shape. The columnar portion 104a is formed of a composite material of powder or flakes and plastic made of a magnetic material or ferrite, and the laminated portion 104b is formed of a laminated body of amorphous foil or a laminated body of amorphous foil and plastic film. A small-diameter protrusion 104c is provided at one end of the columnar part 104a. One end of the columnar portion 104a and one end of the stacked portion 104b are directly connected using an adhesive in a state where the protrusion 104c of the columnar portion 104a is inserted into the through hole 104d of the stacked portion 104b. The coil body 16 is wound around the columnar portion 104a. Furthermore, the lamination direction of the amorphous foil etc. of the lamination part 104b is laminated | stacked on the circumferential direction of the lamination part 104b from the ease of lamination | stacking operation | work. In addition, you may laminate | stack the lamination direction, such as an amorphous foil of a lamination | stacking part, not in the circumferential direction but in a horizontal direction or a vertical direction. 1st other than the abovereferenceThe configuration is the same as that.
  In the interrogator antenna 101 configured as described above, the orientation of the magnetic core member 104 is not limited when the magnetic core member 104 is built in the stick, and the RFID interrogator 13 or a battery is installed in the through-hole 104d of the laminated portion 104b. Can be accommodated. As a result, the structure of the RFID interrogator 13 including the antenna 101 can be simplified and the size of the RFID interrogator 13 can be reduced, and the stick can be folded compactly when the stick is not used. Operation other than the above is the firstreferenceSince the operation is substantially the same as that of the embodiment, repeated description is omitted.
[0035]
  25 to 27 show the present invention.7thImplementationofThe form is shown.
  In this embodiment, the columnar portion 104a of the magnetic core member 114 is6thFormed in the same manner as the columnar portion of the embodiment, and the laminated portion 114b6thThe laminated portion of the embodiment is formed in a semi-cylindrical shape that is vertically divided in half. One end of the columnar portion 104a and one end of the stacked portion 114b are directly connected using an adhesive in a state where the protrusion 104c of the columnar portion 104a is inserted into the recessed portion 114d of the stacked portion 114b. The magnetic core member 114 is built into the stick so that the other end of the columnar portion 104a is positioned at the tip of the stick. The coil body 16 is wound around the columnar portion 104a. Further, the lamination direction of the amorphous foil or the like of the lamination part 114b is laminated in the circumferential direction of the lamination part 114b for ease of lamination work. In addition, you may laminate | stack the lamination direction, such as an amorphous foil of a lamination | stacking part, not in the circumferential direction but in a horizontal direction or a vertical direction. The configuration other than the above is the same as that of the first reference embodiment.
  In the interrogator antenna 111 configured as described above, the orientation of the magnetic core member 114 is limited as described above when the magnetic core member 114 is built in the stick, but the cross-sectional area of the stacked portion 114b is the same as that of the columnar portion 104a. Since it is smaller than the cross-sectional area, it is possible to secure a space for accommodating the RFID interrogator 13 and the battery along the laminated portion 114b. As a result, the structure of the RFID interrogator 13 including the antenna 111 can be simplified and the size can be reduced, and the stick can be folded compactly when the stick is not used. Operation other than the above is the firstreferenceSince the operation is substantially the same as that of the embodiment, repeated description is omitted.
[0036]
【Example】
  Next, examples of the present invention will be described in detail together with comparative examples and reference examples.
  <Reference example 1>
  A magnetic core member made of a cylindrical composite material having a diameter × length of 10 mm × 60 mm was produced by injection molding a kneaded product of 92 wt% iron powder and 8 wt% polyethylene. As shown in FIGS. 1 and 2, the magnetic core member has a columnar portion 14a formed in a cylindrical shape having a diameter × length of 7 mm × 30 mm, and a maximum outer diameter × minimum outer diameter × length of 10 mm × 7 mm, respectively. It has a pair of taper parts 14b and 14b which are x15 mm. A coil body 16 was produced by winding a coated copper wire having a diameter of 0.15 mm 390 times around the outer peripheral surface of the columnar portion 14a of the magnetic core member 14 to obtain an interrogator antenna 11. This antenna 11Reference example 1It was.
  <Reference example 2>
  A magnetic core member having the same shape as the magnetic core member of Example 1 was made of ferrite. A coil body was prepared by winding a coated copper wire having a diameter of 0.15 mm on the outer peripheral surface of the columnar part of the magnetic core member 300 times to obtain an interrogator antenna. This antennaReference example 2It was.
[0037]
  <Example 1>
  Magnetic core memberReference example 14 and 5, the diameter of the hole is increased from both end faces of the magnetic core member 34 toward the columnar portion 14a in the pair of taper portions 14b and 14b. A pair of taper holes 34c, 34c are formed. These taper holes 34c and 34c had a maximum inner diameter × length of 7 mm × 15 mm, respectively. A coil body 16 was produced by winding a coated copper wire having a diameter of 0.15 mm around the outer peripheral surface of the columnar portion 14a of the magnetic core member 34 to obtain the interrogator antenna 31. This antenna 31Example 1It was.
  <Reference example 3>
  As shown in FIGS. 6 and 7, a cylindrical shape having an outer diameter × inner diameter × length of 10 mm × 7 mm × 60 mm is obtained by injection molding a kneaded product of 92% by weight of iron powder and 8% by weight of polyethylene. A magnetic core member made of the composite material was prepared. A coil body 16 was manufactured by winding a coated copper wire having a diameter of 0.15 mm around the central outer peripheral surface of the magnetic core member 44 to obtain the interrogator antenna 41. This antenna 41Reference example 3It was.
[0038]
  <Example 2>
  A columnar part 54a made of a square columnar composite material having a length × width × length of 7 mm × 7 mm × 30 mm was produced by injection molding a kneaded product of 92 wt% iron powder and 8 wt% polyethylene. (FIGS. 8 to 10). On the other hand, an amorphous foil (METGLAS2705A: manufactured by Allied Chemical Co., Ltd.) having a thickness of 25 μm and a PET (polyethylene terephthalate) film having a thickness of 0.25 mm are alternately laminated to have a length × width × length of 10 mm × 10 mm × 12 mm. A pair of stacked portions 54b and 54b was formed. A pair of quadrangular frustums 54c and 54c, which gradually increase with distance from both ends of the columnar portion 54a, are integrally formed with the columnar portion 54a by the composite material at both ends of the columnar portion 54a. The magnetic core member 54 was produced by bonding the pair of laminated portions 54b and 54b to the end faces of the pair of square frustums 54c and 54c using an adhesive. A coil body 16 was produced by winding a coated copper wire having a diameter of 0.15 mm 320 times on the outer peripheral surface of the columnar portion 54a of the magnetic core member 54, and the interrogator antenna 51 was obtained. This antenna 51Example 2It was.
  <Example 3>
  A square columnar portion of length × width × length 7 mm × 7 mm × 30 mm was made of ferrite. A pair of laminated partsExample 2It was produced in the same manner as the pair of laminated parts. Note that a pair of square frustums that gradually increase in thickness as the distance from both ends of the columnar portion is formed integrally with the columnar portion by using the ferrite at both ends of the columnar portion. A magnetic core member was produced by bonding a pair of laminated portions to the end faces of a pair of quadrangular pyramids using an adhesive. A coil body was prepared by winding a coated copper wire having a diameter of 0.15 mm 330 times around the outer peripheral surface of the columnar portion of the magnetic core member to obtain an interrogator antenna. This antennaExample 3It was.
[0039]
  <Reference example 4>
  As shown in FIGS. 11 and 12, an amorphous foil (METGLAS2705A: Allied Chemical Co.) having a thickness of 25 μm and a PET (polyethylene terephthalate) film having a thickness of 0.25 mm are alternately laminated to form a length × width. X A magnetic core member 64 having a length of 10 mm x 10 mm x 60 mm was formed. A coil body 16 was produced by winding 290 turns of a coated copper wire having a diameter of 0.15 mm on the outer peripheral surface of the center of the magnetic core member 64, and an interrogator antenna 61 was obtained. This antenna 61Reference example 4It was.
  <Example 4>
  As shown in FIGS. 13 to 15, a rectangular columnar columnar portion 74 a having a length × width × length of 7 mm × 7 mm × 30 mm was produced from ferrite. Further, an amorphous foil (METGLAS2705A: manufactured by Allied Chemical Co., Ltd.) having a thickness of 20 μm and a PET (polyethylene terephthalate) film having a thickness of 0.5 mm are alternately laminated to have a length × width × length of 10 mm × 10 mm × 30 mm. A quadrangular columnar laminated portion 74b was prepared. A magnetic core member 74 was obtained by connecting one end of the columnar portion 74a and one end of the laminated portion 74b using an adhesive. A coil main body 16 was produced by winding 280 turns of a coated copper wire having a diameter of 0.15 mm around the columnar portion 74a of the magnetic core member 74, and an interrogator antenna 71 was obtained. This antenna 71Example 4It was.
[0040]
  <Example 5>
  As shown in FIGS. 16 to 18, a rectangular columnar shape having a length × width × length of 7 mm × 7 mm × 30 mm is obtained by injection molding a kneaded product of 92 wt% iron powder and 8 wt% polyethylene. A columnar portion 74a made of a composite material was produced. Further, an amorphous foil having a thickness of 20 μm (METGLAS2705A: manufactured by Allied Chemical Co., Ltd.) and a PET (polyethylene terephthalate) film having a thickness of 0.5 mm are alternately laminated to have a length × width × length of 10 mm × 10 mm × 30 mm. A quadrangular columnar laminated portion 84b was prepared. A magnetic core member was obtained by connecting one end of the columnar portion 74a and one end of the laminated portion 84b using an adhesive. A coil body 16 was prepared by winding a coated copper wire having a diameter of 0.15 mm around the columnar portion 74a of the magnetic core member 84 to obtain the interrogator antenna 81. This antenna 81Example 5It was.
  <Example 6>
  As shown in FIGS. 19 to 21, a rectangular columnar shape having a length × width × length of 7 mm × 7 mm × 30 mm is formed by injection molding a kneaded product of 92 wt% iron powder and 8 wt% polyethylene. A columnar portion 74a made of a composite material was produced. Further, an amorphous foil (METGLAS2705A: manufactured by Allied Chemical Co., Ltd.) having a thickness of 20 μm and a PET (polyethylene terephthalate) film having a thickness of 0.5 mm are alternately laminated to have a length × width × length of 10 mm × 1.5 mm. Two square columnar laminated portions 94b and 94b each having a size of 30 mm were produced. A magnetic core member 94 was obtained by connecting one end of the two laminated portions 94b and 94b to one end of the columnar portion 74a with an adhesive at a predetermined interval in the vertical direction. A coil body 16 was produced by winding a coated copper wire having a diameter of 0.15 mm around the columnar portion 74a of the magnetic core member 94 to obtain the interrogator antenna 91. This antenna 91Example 6It was.
[0041]
  <Example 7>
  As shown in FIG. 22 to FIG. 24, a cylindrical composite material having an outer diameter × length of 7 mm × 30 mm is obtained by injection molding a kneaded product of 92 wt% iron powder and 8 wt% polyethylene. The columnar part 104a was produced. A projection 104c having an outer diameter of 6 mm is provided at one end of the columnar portion 104a. Further, an amorphous foil (METGLAS2705A: manufactured by Allied Chemical Co., Ltd.) having a thickness of 20 μm and a PET (polyethylene terephthalate) film having a thickness of 0.1 mm are alternately laminated to have an outer diameter × inner diameter × length of 7 mm × 6 mm × A 30-mm cylindrical laminated portion 104b was produced. The magnetic core member 104 was obtained by inserting the protrusion 104c of the columnar part 104a into the through hole 104d from one end of the laminated part 104b and connecting it using an adhesive. A coil body 16 was produced by winding a coated copper wire having a diameter of 0.15 mm around the columnar portion 104a of the magnetic core member 104 to obtain the interrogator antenna 101. This antenna 101Example 7It was.
  <Example 8>
  As shown in FIG. 25 to FIG. 27, a cylindrical composite material having an outer diameter × length of 7 mm × 30 mm is obtained by injection molding a kneaded product of 92 wt% iron powder and 8 wt% polyethylene. The columnar part 104a was produced. A projection 104c having an outer diameter of 6 mm is provided at one end of the columnar portion 104a. In addition, 20 μm thick amorphous foil (METGLAS2705A: manufactured by Allied Chemical Co., Ltd.) and 0.1 mm thick PET (polyethylene terephthalate) film are alternately laminated to obtain an outer diameter × inner diameter × length of 7 mm × 5 mm × 30 mm. A semi-cylindrical laminated portion 114b was produced. The magnetic core member 114 was obtained by inserting the protrusion 104c of the columnar part 104a into the concave part 114d from one end of the laminated part 114b and connecting it using an adhesive. A coil body 16 was manufactured by winding a coated copper wire having a diameter of 0.15 mm around the columnar portion 104a of the magnetic core member 114 to obtain the interrogator antenna 111. This antenna 111Example 8It was.
[0042]
<Comparative Example 1>
A magnetic core member made of a cylindrical composite material having a diameter × length of 10 mm × 60 mm was produced by injection molding a kneaded product of 92 wt% iron powder and 8 wt% polyethylene. A coil body was produced by winding a coated copper wire having a diameter of 0.15 mm around the center outer peripheral surface of the magnetic core member 340 times to obtain an interrogator antenna. This antenna was referred to as Comparative Example 1.
[0043]
  <Comparative test 1 and evaluation>
  Example 18, Reference Examples 1-4And both ends of the antenna coil of the interrogator antenna of Comparative Example 1 are respectively connected to the interrogator, and these antennas are RFID tags (consisting of a tag antenna and an IC chip (HT1 MOA2 S30: manufactured by Philips Semiconductors)). The distance between the interrogator antenna and the tag antenna when the tag was activated was gradually measured. The RFID tag includes a tag antenna and an IC chip (HT1 MOA2 S30: manufactured by Philips Semiconductors) connected to the antenna. The tag antenna is formed by winding 340 turns of a magnetic core member made of the same material and in the same shape as the magnetic core member of Comparative Example 1, and a coated copper wire having a diameter of 0.15 mm around the center outer peripheral surface of the magnetic core member. And a formed coil body.
Moreover, the Q value of the resonance circuit comprised by the self-inductance of each interrogator antenna and the interrogator antenna and the capacitor in the interrogator was measured using a Q meter. The Q value was measured by changing the frequency of radio waves in the range of 0.1 MHz to 20 MHz. These measured values are shown in Table 1 together with the material and weight of the magnetic core member and the number of turns of the coil body.
[0044]
[Table 1]
Figure 0004078807
[0045]
  As is apparent from Table 1, in Comparative Example 1, a relatively heavy columnar magnetic core member having a weight of 23.56 g was used, so that the working distance was relatively long at 60 cm and the Q value was relatively large at 85. An interrogator antenna was obtained. On the other hand, Examples 1 to8as well asReference Examples 1-3Then, even when using a magnetic core member having a weight of 12.02 to 15.30 g, which is about half that of Comparative Example 1, the working distance and Q value are substantially the same as Comparative Example 1, that is, the working distance is 55 to 61 cm. An interrogator antenna having a long Q value of 69 to 93 was obtained. AlsoReference example 4Then, although the Q value was as small as 25, a magnetic core member having an extremely light weight of about 40% of that of Comparative Example 1 could be obtained.
[0046]
【The invention's effect】
As described above, according to the present invention, the columnar portion of the magnetic core member is formed into a columnar shape by a composite material of powder or flakes and plastic made of a magnetic material or by ferrite, and the columnar portion is separated from the columnar portion at both ends. Accordingly, a pair of taper portions that are gradually thicker are provided, so that the magnetic core member becomes lighter than the conventional columnar magnetic core member having the diameter of the thickest portion of the pair of taper portions. The working distance of the conventional antenna is substantially the same as the working distance of the antenna using the conventional magnetic core member. As a result, the RFID tag using the antenna of the present invention is excellent in portability. In addition, since the cross section through which the magnetic flux passes is reduced in the columnar part, it is necessary to increase the number of turns of the coil body. However, since the coil body is wound around the thin columnar part, the overall length of the coil body is shortened and its electric resistance is reduced. As a result, the Q value of the resonance circuit composed of the antenna and the capacitor of the present invention increases, and the resonance width becomes sharper.
[0047]
  In addition, if one or both of the pair of tapered portions is formed with a tapered hole whose hole diameter is reduced from the end face of the magnetic core member toward the columnar portion, the magnetic core member can be further lightened and The working distance of the antenna using the core member can be made substantially the same as the working distance of the antenna using the conventional magnetic core member.The
  Further, a columnar portion around which the coil body is wound is formed of a magnetic material powder or flake and plastic composite material or a columnar shape with ferrite, and a pair of amorphous laminate or amorphous foil and plastic film laminate. If the laminated parts are bonded to both ends of the columnar part, eddy currents are not generated in the central columnar part of the magnetic core member, so there is little high-frequency loss, and the antenna and capacitor using this magnetic core member are used. The Q value of the resonance circuit does not decrease. In addition, since the pair of stacked portions is lightweight, the weight of the entire antenna can be reduced.
[0048]
  Further, if the cross-sectional area of the columnar part having a relatively large specific gravity is made smaller than the cross-sectional area of the pair of laminated parts having a relatively small specific gravity, the weight of the entire antenna can be further reduced. In addition, since the cross section through which the magnetic flux passes is reduced in the columnar part, it is necessary to increase the number of turns of the coil body. However, since the coil body is wound around the thin columnar part, the overall length of the coil body is shortened and its electric resistance is reduced. The Q value of a resonance circuit composed of an antenna and a capacitor using this magnetic core member becomes large and the resonance width becomes sharp.The
[0049]
Further, if the columnar portion of the magnetic core member is formed in a columnar shape with ferrite or the like, and the laminated portion formed in a columnar shape by a laminated body of amorphous foil or the like is connected to one end of the columnar portion, the magnetic core member includes the magnetic core member. Since the eddy current is less likely to occur and the high-frequency loss is reduced, the Q value of the resonance circuit including the antenna and the capacitor using the magnetic core member is higher than the Q value of the resonance circuit using the magnetic core member. .
In addition, if the cross-sectional area of the stacked portion is formed smaller than the cross-sectional area of the columnar portion, the cross-sectional area of the stacked portion is smaller than the cross-sectional area of the columnar portion, so that it is possible to secure a space for accommodating electronic components and batteries along the stacked portion. . As a result, the structure of the RFID interrogator including the antenna is simplified, and the antenna using the magnetic core member can be downsized.
Further, if a slit extending in the longitudinal direction is formed in the laminated portion, an electronic component, a battery, or the like can be accommodated in the slit of the laminated portion. As a result, the same effect as described above can be obtained.
[0050]
Also, if the columnar part of the magnetic core member is formed in a columnar shape with ferrite or the like, and the laminated part formed in a cylindrical shape by a laminated body of amorphous foil or the like is connected to one end of the columnar part, an electronic component or A battery or the like can be accommodated. As a result, the same effect as described above can be obtained.
Furthermore, if the columnar part of the magnetic core member is formed into a columnar shape by ferrite or the like, and the laminated part formed in a semi-cylindrical shape by a laminated body of amorphous foil or the like is connected to one end of the columnar part, the cross-sectional area of the laminated part is Therefore, it is possible to secure a space for accommodating electronic components, batteries, and the like along the laminated portion. As a result, the same effect as described above can be obtained.
[Brief description of the drawings]
[Figure 1]First reference formThe principal part fracture side view which shows the antenna for interrogators of RFID interrogator of.
FIG. 2 is a view taken in the direction of arrow A in FIG.
FIG. 3 is a configuration diagram of an RFID interrogator and an RFID tag showing a state in which the interrogator antenna is opposed to the tag antenna.
FIG. 4 of the present inventionFirstThe principal part fracture side view corresponding to Drawing 1 showing an embodiment.
FIG. 5 is a view taken in the direction of arrow B in FIG.
[Fig. 6]Second reference formThe principal part fracture | rupture side view corresponding to FIG.
7 is a cross-sectional view taken along line CC in FIG.
[Fig. 8] of the present inventionSecondThe principal part fracture side view corresponding to Drawing 1 showing an embodiment.
FIG. 9 is a view taken in the direction of arrow D in FIG.
FIG. 10 is a perspective view of the antenna.
FIG. 11Third reference formThe principal part fracture | rupture side view corresponding to FIG.
12 is a cross-sectional view taken along line EE in FIG.
FIG. 13 shows the present invention.ThirdThe longitudinal cross-sectional view of the magnetic core member which shows embodiment.
14 is a cross-sectional view taken along line FF in FIG.
15 is a cross-sectional view taken along line GG in FIG.
FIG. 16 shows the present invention.4thThe longitudinal cross-sectional view of the magnetic core member which shows embodiment.
17 is a cross-sectional view taken along line HH in FIG.
18 is a cross-sectional view taken along the line II of FIG.
FIG. 19 shows the present invention.5thThe longitudinal cross-sectional view of the magnetic core member which shows embodiment.
20 is a sectional view taken along line JJ of FIG.
FIG. 21 is a sectional view taken along line KK in FIG.
FIG. 22 shows the present invention.6thThe longitudinal cross-sectional view of the magnetic core member which shows embodiment.
23 is a cross-sectional view taken along line LL in FIG.
24 is a cross-sectional view taken along line MM in FIG.
FIG. 25 shows the present invention.7thThe longitudinal cross-sectional view of the magnetic core member which shows embodiment.
26 is a sectional view taken along line NN in FIG. 25. FIG.
27 is a sectional view taken along the line PP in FIG. 25. FIG.
[Explanation of symbols]
  11, 31, 41, 51, 61, 71, 81, 91, 101, 111 Interrogator antenna (RFID antenna)
  14, 34, 44, 54, 64, 74, 84, 94, 104, 114 Magnetic core member
  14a, 54a, 74a, 104a Columnar part
  14b Taper part
  16 Coil body
  34c taper hole
  44a through hole
  54b, 74b, 84b, 94b, 104b, 114b
  94c slit

Claims (8)

磁芯部材(34)にコイル本体(16)を巻回することにより形成されたＲＦＩＤ用アンテナにおいて、
前記磁芯部材(34)が、磁性材料からなる粉末若しくはフレーク及びプラスチックの複合材により或いはフェライトにより柱状に形成され前記コイル本体(16)が巻回される柱状部(14a)と、前記柱状部(14a)の両端に設けられ前記柱状部(14a)から離れるに従って次第に太くなる一対のテーパ部(14b,14b)と、前記一対のテーパ部 (14b,14b) のいずれか一方又は双方に形成され磁芯部材 (14) の端面から柱状部 (14a) に向うに従って穴径が小さくなるテーパ穴 (34c,34c) とを有することを特徴とするＲＦＩＤ用アンテナ。In the RFID antenna formed by winding the coil body (16) around the magnetic core member ( 34 ),
The magnetic core member ( 34 ) is formed of a magnetic material powder or flake and plastic composite material, or is formed in a columnar shape from ferrite, and the columnar portion (14 a) around which the coil body (16) is wound, and the columnar portion (14a) provided at both ends of the pair of tapered portions (14b, 14b) that gradually increase in thickness as the distance from the columnar portion (14a) increases, and is formed on one or both of the pair of tapered portions (14b, 14b). magnetic core member (14) of the hole diameter becomes smaller as toward the columnar portion (14a) from the end face tapered hole (34c, 34c) and the RFID antenna characterized by having a. 磁芯部材(54)にコイル本体(16)を巻回することにより形成されたＲＦＩＤ用アンテナにおいて、
前記磁芯部材(54)が、磁性材料からなる粉末若しくはフレーク及びプラスチックの複合材により或いはフェライトにより柱状に形成され前記コイル本体(16)が巻回される柱状部(54a)と、前記柱状部(54a)の両端にそれぞれ接着されアモルファスの積層体或いはアモルファス箔及びプラスチックフィルムの積層体により形成された一対の積層部(54b,54b)とを有することを特徴とするＲＦＩＤ用アンテナ。In the RFID antenna formed by winding the coil body (16) around the magnetic core member (54),
The magnetic core member (54) is formed of a magnetic material powder or flake and plastic composite material or in a columnar shape with ferrite, and the columnar portion (54a) around which the coil body (16) is wound, and the columnar portion An RFID antenna comprising a pair of laminated portions (54b, 54b) formed of an amorphous laminated body or a laminated body of an amorphous foil and a plastic film, which are respectively bonded to both ends of (54a). 柱状部(54a)の横断面積が一対の積層部(54b,54b)の横断面積より小さく形成された請求項２記載のＲＦＩＤ用アンテナ。The RFID antenna according to claim 2, wherein a cross-sectional area of the columnar part (54a) is smaller than a cross-sectional area of the pair of laminated parts (54b, 54b). 磁芯部材(74)にコイル本体(16)を巻回することにより形成されたＲＦＩＤ用アンテナにおいて、
前記磁芯部材(74)が、磁性材料からなる粉末若しくはフレーク及びプラスチックの複合材により或いはフェライトにより柱状に形成された柱状部(74a)と、前記柱状部(74a)の一端に接続されアモルファス箔の積層体或いはアモルファス箔及びプラスチックフィルムの積層体により柱状に形成された積層部(74b)とを有し、
前記積層部 (74b) が、前記柱状部 (74a) の一端に接着剤を用いて直接接続されるか或いは前記柱状部 (74a) 及び前記積層部 (74b) をベース板に接着剤を用いて接着することにより前記柱状部 (74a) の一端に間接的に接続されることを特徴とするＲＦＩＤ用アンテナ。In the RFID antenna formed by winding the coil body (16) around the magnetic core member (74),
The magnetic core member (74) is connected to one end of the columnar portion (74a), and a columnar portion (74a) formed in a columnar shape by a composite material of powder or flakes and plastic made of a magnetic material or by ferrite. laminated portion formed in a columnar shape by laminate or amorphous foil and laminates of plastic films and (74b) possess,
The stacked portion (74b) is directly connected to one end of the columnar portion (74a) using an adhesive, or the columnar portion (74a) and the stacked portion (74b) are bonded to a base plate using an adhesive. RFID antenna, wherein Rukoto indirectly connected to one end of the columnar portion (74a) by bonding. 積層部(84b)の横断面積が柱状部(84a)の横断面積より小さく形成された請求項４記載のＲＦＩＤ用アンテナ。The RFID antenna according to claim 4, wherein a cross-sectional area of the laminated portion (84b) is smaller than a cross-sectional area of the columnar portion (84a). 積層部が、柱状部 (74a) の一端にこの柱状部 (74a) の長手方向に直交する方向に所定のスペース(94c)をあけた状態でそれぞれ接続された一対の積層部 (94b,94b) である請求項４記載のＲＦＩＤ用アンテナ。 Product layer portion, one end pair of the laminate state Desolation respectively connected to spaced a predetermined space (94c) in a direction perpendicular to the longitudinal direction of the columnar portion (74a) of the columnar portion (74a) ( 94b, 94b) an RFID antenna according to claim 4, wherein. 磁芯部材(104)にコイル本体(16)を巻回することにより形成されたＲＦＩＤ用アンテナにおいて、
前記磁芯部材(104)が、磁性材料からなる粉末若しくはフレーク及びプラスチックの複合材により或いはフェライトにより柱状に形成された柱状部(104a)と、前記柱状部(104a)の一端に接着剤を用いて直接接続されアモルファス箔の積層体或いはアモルファス箔及びプラスチックフィルムの積層体により筒状に形成された積層部(104b)とを有することを特徴とするＲＦＩＤ用アンテナ。In the RFID antenna formed by winding the coil body (16) around the magnetic core member (104),
The magnetic core member (104) is made of a magnetic material powder or flake and plastic composite material or a columnar part (104a) formed in a columnar shape from ferrite, and an adhesive is used at one end of the columnar part (104a). And a laminated portion (104b) formed in a cylindrical shape by a laminated body of amorphous foil or a laminated body of amorphous foil and plastic film. 磁芯部材(114)にコイル本体(16)を巻回することにより形成されたＲＦＩＤ用アンテナにおいて、
前記磁芯部材(114)が、磁性材料からなる粉末若しくはフレーク及びプラスチックの複合材により或いはフェライトにより柱状に形成された柱状部(104a)と、前記柱状部(104a)の一端に接着剤を用いて直接接続されアモルファス箔の積層体或いはアモルファス箔及びプラスチックフィルムの積層体により半筒状に形成された積層部(114b)とを有することを特徴とするＲＦＩＤ用アンテナ。In the RFID antenna formed by winding the coil body (16) around the magnetic core member (114),
The magnetic core member (114) is made of a composite material of powder or flakes made of a magnetic material and a plastic or a columnar portion (104a) formed in a columnar shape from ferrite, and an adhesive is used at one end of the columnar portion (104a). And a laminated portion (114b) formed in a semi-cylindrical shape by a laminated body of amorphous foil or a laminated body of amorphous foil and plastic film.
JP2001036706A 2000-11-06 2001-02-14 RFID antenna Expired - Fee Related JP4078807B2 (en)

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