JPH10224276A - Automatic electromagnetic induction type recognition device - Google Patents
Automatic electromagnetic induction type recognition deviceInfo
- Publication number
- JPH10224276A JPH10224276A JP2414997A JP2414997A JPH10224276A JP H10224276 A JPH10224276 A JP H10224276A JP 2414997 A JP2414997 A JP 2414997A JP 2414997 A JP2414997 A JP 2414997A JP H10224276 A JPH10224276 A JP H10224276A
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- Prior art keywords
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- circuit
- antenna coil
- interrogation
- signal
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- 230000005674 electromagnetic induction Effects 0.000 title claims description 13
- 230000004044 response Effects 0.000 claims abstract description 42
- 230000005540 biological transmission Effects 0.000 claims abstract description 11
- 239000003990 capacitor Substances 0.000 claims description 34
- 230000005291 magnetic effect Effects 0.000 claims description 33
- 230000007704 transition Effects 0.000 claims description 7
- 238000012423 maintenance Methods 0.000 claims 2
- 230000008054 signal transmission Effects 0.000 description 11
- 238000010586 diagram Methods 0.000 description 8
- 230000007423 decrease Effects 0.000 description 6
- 238000001514 detection method Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 230000008859 change Effects 0.000 description 2
- 239000000446 fuel Substances 0.000 description 2
- 238000002347 injection Methods 0.000 description 2
- 239000007924 injection Substances 0.000 description 2
- 229910000859 α-Fe Inorganic materials 0.000 description 2
- 230000002411 adverse Effects 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 230000001808 coupling effect Effects 0.000 description 1
- 239000003302 ferromagnetic material Substances 0.000 description 1
- 230000005669 field effect Effects 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 230000005764 inhibitory process Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は車両用盗難防止装置
等に採用するに適した電磁誘導式自動認識装置に関す
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic induction type automatic recognition device suitable for use in a vehicle anti-theft device and the like.
【０００２】[0002]
【従来の技術】従来、この種の電磁誘導式自動認識装置
に採用される質問器には、図７にて示すごとく、構成し
たものがある（特開平５−２５２０８１号公報にて示す
類例参照）。この質問器は、質問用アンテナコイル１
と、このアンテナコイル１と共に共振回路を構成する共
振用コンデンサ２とを備える。また、この質問器は、制
御回路３に接続した送信回路４と、この送信回路４とア
ンテナコイル１との間に接続した駆動回路５と、制御回
路３とアンテナコイル１及びコンデンサ２の共通端子１
ａとの間に接続した復調回路６とを備える。ここで、駆
動回路５は、Ｐチャンネル型及びＮチャンネル型の両電
界効果トランジスタ５ａ、５ｂ（以下、ＦＥＴ５ａ、５
ｂという）をハーフブリッジ構成に接続したものであ
る。2. Description of the Related Art Conventionally, there is an interrogator employed in this type of electromagnetic induction type automatic recognition apparatus as shown in FIG. 7 (refer to a similar example disclosed in Japanese Patent Application Laid-Open No. H5-252581). ). This interrogator is a question antenna coil 1
And a resonance capacitor 2 that forms a resonance circuit together with the antenna coil 1. The interrogator includes a transmitting circuit 4 connected to the control circuit 3, a driving circuit 5 connected between the transmitting circuit 4 and the antenna coil 1, and a common terminal for the control circuit 3, the antenna coil 1 and the capacitor 2. 1
a) and a demodulation circuit 6 connected between the two. Here, the drive circuit 5 includes both P-channel and N-channel field effect transistors 5a and 5b (hereinafter, FETs 5a and 5b).
b) is connected to a half-bridge configuration.
【０００３】そして、この質問器は、通常、応答器との
通信を行うにあたり、図８で示すように、チャージ期
間、質問信号送信期間及び応答信号受信期間の三つの期
間に亘る時分割作動を行う。ここで、チャージ期間は、
質問器から応答器へ高周波電力を供給する期間であり、
質問信号送信期間は、質問器から応答器へ質問信号を送
信する期間であり、応答信号受信期間は、質問器が応答
器から応答信号を受信する期間である。In order to communicate with a transponder, this interrogator normally performs a time-sharing operation over three periods of a charge period, an interrogation signal transmission period and a response signal reception period as shown in FIG. Do. Here, the charge period is
This is the period for supplying high frequency power from the interrogator to the responder,
The interrogation signal transmission period is a period during which the interrogator transmits an interrogation signal to the transponder, and the response signal reception period is a period during which the interrogator receives the response signal from the transponder.
【０００４】この時分割作動において、チャージ期間で
は、応答器に通信に必要な高周波電力を供給するため、
制御回路３が、ローレベルにて制御信号（図８にて符号
Ａ参照）を発生すると、送信回路４は、この制御信号Ａ
を受けて、搬送周波数ｆ及び振幅Ｖｃのクロックパルス
（図８にて符号Ｂ参照）を駆動回路５に出力する。この
ため、両ＦＥＴ５ａ、５ｂが、その各ゲート端子にて、
送信回路４からクロックパルスＢを順次受けると、これ
ら両ＦＥＴ５ａ、５ｂの各ゲート電圧が零（Ｖ）のと
き、ＦＥＴ５ａがオフすると同時にＦＥＴ５ｂがオンす
る。また、上記各ゲート電圧が正の振幅Ｖｃのとき、逆
にＦＥＴ５ａがオンすると同時にＦＥＴ５ｂがオフす
る。In this time-sharing operation, during the charging period, high-frequency power necessary for communication is supplied to the transponder,
When the control circuit 3 generates a control signal at a low level (see reference symbol A in FIG. 8), the transmission circuit 4
In response to this, a clock pulse having a carrier frequency f and an amplitude Vc (see reference sign B in FIG. 8) is output to the drive circuit 5. For this reason, both FETs 5a and 5b are connected at their respective gate terminals.
When the clock pulse B is sequentially received from the transmission circuit 4, when the gate voltages of the two FETs 5a and 5b are zero (V), the FET 5a turns off and the FET 5b turns on at the same time. When each gate voltage has a positive amplitude Vc, the FET 5a is turned on and the FET 5b is turned off at the same time.
【０００５】よって、両ＦＥＴ５ａ、５ｂが交互にオン
オフされることにより、アンテナコイル１とコンデンサ
２は、ＦＥＴ５ｂのオン毎に周波数ｆにて直列共振す
る。アンテナコイル１はこの直列共振に基づき磁界を発
生し、当該磁界を媒体として端子電圧（図８にて符号Ｃ
参照）に対応する高周波電力を応答器に供給する。但
し、アンテナコイル１のインダクタンスをＬとし、コン
デンサ２の静電容量をＣとしたとき、次の数１の式が成
立するようにインダクタンスＬ及び静電容量Ｃが調整さ
れている。[0005] Therefore, when the FETs 5a and 5b are alternately turned on and off, the antenna coil 1 and the capacitor 2 resonate in series at the frequency f each time the FET 5b is turned on. The antenna coil 1 generates a magnetic field based on the series resonance, and uses the magnetic field as a medium to generate a terminal voltage (C in FIG. 8).
) Is supplied to the transponder. However, when the inductance of the antenna coil 1 is L and the capacitance of the capacitor 2 is C, the inductance L and the capacitance C are adjusted so that the following equation 1 is satisfied.
【０００６】[0006]
【数１】ｆ＝１／２π（ＬＣ）-1/2 なお、応答器は、上記磁界を受信したときこの受信磁界
（図８にて符号Ｄ参照）でもって電力を供給される。次
に、質問信号送信期間では、制御回路３が、質問内容を
表す複数ビットからなる質問信号を制御信号として発生
する。F = 1 / 2π (LC) -1/2 When the transponder receives the above magnetic field, the transponder is supplied with power by the received magnetic field (refer to the symbol D in FIG. 8). Next, in the interrogation signal transmission period, the control circuit 3 generates an interrogation signal composed of a plurality of bits representing the content of the interrogation as a control signal.
【０００７】ここで、質問信号は、「１」を表すビット
（以下、Ｈビットという）及び「０」を表すビット（以
下、Ｌビットという）の集合からなる。また、Ｈビット
及びＬビットは、共に、ハイレベル期間とローレベル期
間とにより構成されており、質問信号のＰＷＭ符号化
は、これら各Ｈビット及びＬビットのハイレベル期間と
ローレベル期間とを、上記質問内容を特定すべく互いに
異ならしめることで行われている。Here, the interrogation signal is composed of a set of bits representing "1" (hereinafter, referred to as H bits) and bits representing "0" (hereinafter, referred to as L bits). Further, both the H bit and the L bit are constituted by a high level period and a low level period, and the PWM encoding of the interrogation signal is performed by dividing the high level period and the low level period of each of the H bit and the L bit. This is done by differentiating each other in order to identify the content of the above question.
【０００８】このため、制御回路３の制御信号は、上記
質問信号の内容に対応してＰＷＭ符号化された信号（図
８にて符号Ａ１参照）となる。すると、送信回路４が、
制御回路３からＰＷＭ符号化制御信号Ａ１を受けてＰＷ
Ｍ符号化パルス（図８にて符号Ｂ１参照）を駆動回路５
に出力する。このため、この駆動回路５では、両ＦＥＴ
５ａ、５ｂがＰＷＭ符号化パルスＢ１によりＰＷＭ制御
されてオンオフする。これに伴い、この駆動回路５のＰ
ＷＭ作動のもと、アンテナコイル１とコンデンサ２は、
ＦＥＴ５ａのオフ及びＦＥＴ５ｂのオンの時に直列共振
し、ＦＥＴ５ａのオン及びＦＥＴ５ｂのオフの時に並列
共振する。For this reason, the control signal of the control circuit 3 is a signal (see reference numeral A1 in FIG. 8) PWM-coded in accordance with the contents of the inquiry signal. Then, the transmission circuit 4
Upon receiving the PWM coding control signal A1 from the control circuit 3,
The M coded pulse (refer to the code B1 in FIG. 8)
Output to Therefore, in this drive circuit 5, both FETs
5a and 5b are turned on and off under PWM control by the PWM coding pulse B1. Accordingly, the P of the driving circuit 5
Under the WM operation, the antenna coil 1 and the capacitor 2
A series resonance occurs when the FET 5a is turned off and the FET 5b is turned on, and a parallel resonance occurs when the FET 5a is turned on and the FET 5b is turned off.
【０００９】これに伴い、アンテナコイル１ａが、上記
ＰＷＭ制御に応じた直列共振及びこの直列共振を停止さ
せる並列共振に基づき、ＰＷＭ符号化によるＡＭ変調を
かけた質問用磁界（図８にて符号Ｃ１参照）を発生する
とともにこの磁界を媒体として質問信号を応答器に送信
する。すると、この応答器は、その応答用アンテナコイ
ルにて、上記質問用磁界を受信磁界（図８にて符号Ｄ１
参照）として受信し、この受信磁界を媒体として質問信
号を受信する。Accordingly, the antenna coil 1a generates an interrogation magnetic field (denoted in FIG. 8) by applying AM modulation by PWM coding based on the series resonance according to the PWM control and the parallel resonance for stopping the series resonance. C1) and transmits an interrogation signal to the transponder using the magnetic field as a medium. Then, the transponder uses the response antenna coil to transmit the interrogation magnetic field to the reception magnetic field (D1 in FIG. 8).
), And an interrogation signal is received using the received magnetic field as a medium.
【００１０】ついで、応答器は、受信質問信号のレベル
が閾値（図８参照）よりも低下する幅を検出して質問信
号を復調信号（図８にて符号Ｅ１参照）として復調し、
この復調信号に基づき所定のＩＤコードを応答用アンテ
ナコイルから応答用磁界を媒体として応答信号として質
問器に返信する。ついで、応答信号受信期間では、制御
回路３がハイレベルの制御信号（図８にて符号Ａ２参
照）を発生する。このため、送信回路４がその出力をハ
イレベルＶｃ（図８にて符号Ｂ２参照）に維持する。Next, the transponder detects a width in which the level of the received interrogation signal is lower than the threshold value (see FIG. 8), and demodulates the interrogation signal as a demodulated signal (see symbol E1 in FIG. 8).
Based on this demodulated signal, a predetermined ID code is returned from the response antenna coil to the interrogator as a response signal using the response magnetic field as a medium. Next, during the response signal receiving period, the control circuit 3 generates a high-level control signal (see A2 in FIG. 8). For this reason, the transmission circuit 4 maintains its output at the high level Vc (see reference numeral B2 in FIG. 8).
【００１１】従って、駆動回路５が、ＦＥＴ５ａをオン
状態に維持するとともにＦＥＴ５ｂをオフ状態に維持す
る。このため、アンテナコイル１が、その一端子１ｂに
て、接地されて、応答用磁界を受信しコンデンサ２と共
に並列共振する。このとき、アンテナコイル１の端子電
圧は零（図８にて符号Ｃ２参照）となる。これに伴い、
アンテナコイル１は、その並列共振のもと、応答器から
応答信号を受信し、復調回路６は、アンテナコイル１の
受信信号を共振電圧として、アンテナコイル１とコンデ
ンサ２との共通端子１ａから受けて増幅した後復調し復
調信号として制御回路３に出力する。Therefore, the drive circuit 5 keeps the FET 5a on and keeps the FET 5b off. Therefore, the antenna coil 1 is grounded at one terminal 1b, receives the response magnetic field, and resonates in parallel with the capacitor 2. At this time, the terminal voltage of the antenna coil 1 becomes zero (refer to the symbol C2 in FIG. 8). Along with this,
The antenna coil 1 receives a response signal from the transponder under the parallel resonance, and the demodulation circuit 6 receives the reception signal of the antenna coil 1 as a resonance voltage from a common terminal 1a of the antenna coil 1 and the capacitor 2. The signal is then demodulated and output to the control circuit 3 as a demodulated signal.
【００１２】これに伴い、制御回路３が、復調回路６か
らの復調信号に基づきＩＤコードとの一致不一致を判定
し、一致時に応答器を正しいものとして認識する。Accordingly, the control circuit 3 determines whether or not the ID code matches with the ID code based on the demodulated signal from the demodulation circuit 6, and recognizes the transponder as correct when the ID code matches.
【００１３】[0013]
【発明が解決しようとする課題】ところで、上記質問信
号送信期間において、アンテナコイル１とコンデンサ２
との直列共振を並列共振に切り換えて停止するとき、ア
ンテナコイル１とコンデンサ２との共通端子１ａに生じ
ている共振電圧（即ち、共振エネルギー）は、上記直列
共振の並列共振への切り換え後における残留振動のた
め、徐々にしか減少しない。また、応答器のアンテナコ
イルには、質問用磁界の集磁効率を高めるために、フェ
ライトコアが用いられている。During the above-mentioned interrogation signal transmission period, the antenna coil 1 and the capacitor 2
When the series resonance is switched to the parallel resonance and stopped, the resonance voltage (that is, the resonance energy) generated at the common terminal 1a of the antenna coil 1 and the capacitor 2 is changed after the series resonance is switched to the parallel resonance. It decreases only gradually due to residual vibration. In addition, a ferrite core is used for the antenna coil of the transponder in order to increase the magnetic flux collection efficiency of the interrogating magnetic field.
【００１４】従って、応答器のアンテナコイルの受信磁
界強度（図８にて各符号Ｍａ、Ｍｂ参照）は、応答器と
質問器との間の距離が短い程高くなる。なお、受信磁界
強度Ｍａは受信磁界強度Ｍｂよりも高い。このため、上
述のように直列共振停止後の残留振動の減少は、応答器
と質問器との間の距離が短い程、遅い。換言すれば、応
答器の受信磁界強度の減少は、図８の符号Ｄ１にて示す
ごとく、応答器と質問器との間の距離が短い程遅い。Accordingly, the received magnetic field strength of the antenna coil of the transponder (see reference numerals Ma and Mb in FIG. 8) increases as the distance between the transponder and the interrogator decreases. The reception magnetic field strength Ma is higher than the reception magnetic field strength Mb. For this reason, as described above, the decrease in the residual vibration after the series resonance stops is slower as the distance between the transponder and the interrogator is shorter. In other words, the decrease in the received magnetic field strength of the transponder is slower as the distance between the transponder and the interrogator is shorter, as indicated by reference numeral D1 in FIG.
【００１５】従って、応答器と質問器との間の距離が短
い程、応答器の受信磁界に含まれる質問信号のレベルが
閾値（図８参照）まで低下する時間が遅れる。よって、
応答器における検出パルスの幅（受信信号のレベルが上
記閾値以下となる幅）が、応答器と質問器との間の距離
が短い程狭い（図８にて各符号Ｅａ、Ｅｂ参照）。な
お、検出パルス幅Ｅａは、検出パルス幅Ｅｂよりの狭
い。Therefore, the shorter the distance between the transponder and the interrogator, the longer the time required for the level of the interrogation signal contained in the received magnetic field of the transponder to drop to the threshold (see FIG. 8). Therefore,
The width of the detection pulse in the transponder (the width at which the level of the received signal is equal to or less than the above threshold) is smaller as the distance between the transponder and the interrogator is shorter (see symbols Ea and Eb in FIG. 8). Note that the detection pulse width Ea is smaller than the detection pulse width Eb.
【００１６】このことは、応答器と質問器との間の距離
が短い程、制御信号即ち質問信号の波形が、応答器の検
出波形において崩れることを意味する。その結果、応答
器が正確に質問信号を復調することができないという不
具合が生ずる。これに対しては、つぎの二つの対策が考
えられる。This means that the shorter the distance between the transponder and the interrogator, the more the waveform of the control signal, that is, the interrogation signal is distorted in the detected waveform of the transponder. As a result, a problem occurs that the transponder cannot accurately demodulate the interrogation signal. To address this, the following two measures can be considered.
【００１７】第１には、直列共振から並列共振への切り
換え時に、アンテナコイル１とコンデンサ２との共通端
子１ａをスイッチング回路で接地させることで、直列共
振の共振エネルギーを逃がし、直列共振の残留振動の吸
収、即ち残留振動エネルギーの放出を急峻に行うことが
考えられる。しかし、その後の応答信号受信期間では、
応答器の応答信号を受信するにあたり、質問器のアンテ
ナコイル１とコンデンサ２とを並列共振させる必要があ
る。このためには、アンテナコイル１とコンデンサ２と
の共通端子１ａの接地をスイッチング回路により解除し
ておく必要がある。First, when switching from series resonance to parallel resonance, the common terminal 1a of the antenna coil 1 and the capacitor 2 is grounded by a switching circuit, so that the resonance energy of the series resonance is released and the series resonance remains. It is conceivable to steeply absorb the vibration, that is, release the residual vibration energy. However, in the subsequent response signal reception period,
In order to receive the response signal of the transponder, it is necessary to resonate the antenna coil 1 and the capacitor 2 of the interrogator in parallel. For this purpose, the grounding of the common terminal 1a of the antenna coil 1 and the capacitor 2 needs to be released by a switching circuit.
【００１８】よって、単に、上記残留振動をスイッチン
グ回路により吸収するのみでは足りない。第２には、ア
ンテナコイル１の線径を小さくする等でアンテナコイル
１の抵抗成分を増やすことが考えられる。ここで、この
抵抗成分は、質問器と応答器との間の目標通信可能距離
を考慮して決める必要がある。しかし、上述のようにア
ンテナコイル１自体の抵抗成分を増やすと、アンテナコ
イル１のコンデンサ２の直列共振時の共振電流のみなら
ず並列共振の共振電流も減少する。Therefore, it is not sufficient to simply absorb the residual vibration by the switching circuit. Second, it is conceivable to increase the resistance component of the antenna coil 1 by reducing the wire diameter of the antenna coil 1 or the like. Here, this resistance component needs to be determined in consideration of the target communicable distance between the interrogator and the transponder. However, when the resistance component of the antenna coil 1 itself is increased as described above, not only the resonance current at the time of series resonance of the capacitor 2 of the antenna coil 1 but also the resonance current of the parallel resonance decreases.
【００１９】このため、直列共振停止後の残留振動を抑
制し得るものの、抵抗値によっては、直列共振時のアン
テナコイル１の発生磁界強度が直列共振エネルギーの減
少のために不足するだけでなく、目標通信可能距離内で
の並列共振時のアンテナコイル１の応答信号受信性能が
並列共振エネルギーの減少のために低下するという不具
合が生ずる。For this reason, although the residual vibration after the series resonance is stopped can be suppressed, depending on the resistance value, not only the intensity of the magnetic field generated by the antenna coil 1 at the time of the series resonance becomes insufficient due to the reduction of the series resonance energy, but also A problem arises in that the response signal receiving performance of the antenna coil 1 at the time of parallel resonance within the target communicable distance is reduced due to a decrease in parallel resonance energy.
【００２０】そこで、本発明は、以上のようなことに対
処するため、質問信号の送信時には直列共振の停止毎に
その残留振動エネルギーを放出し、この放出を次の直列
共振時以前毎に停止するようにした電磁誘導式自動認識
装置を提供することを目的とする。また、本発明は、以
上のようなことに対処するため、質問用アンテナコイル
とは独立的に、質問器内にインピーダンス素子を別途接
続することで、残留振動を抑制しつつ質問信号送信時の
質問器の発生磁界強度を適正に確保し、かつ、目標通信
可能距離内での質問器の応答信号受信性能を良好に維持
するようにした電磁誘導式自動認識装置を提供すること
を目的とする。Therefore, in order to cope with the above, the present invention releases the residual vibration energy every time the series resonance is stopped at the time of transmitting the interrogation signal, and stops the discharge before every next series resonance. It is an object of the present invention to provide an electromagnetic induction type automatic recognition device. Further, the present invention, in order to cope with the above, independently of the antenna coil for interrogation, by separately connecting an impedance element in the interrogator, while suppressing the residual vibration, when transmitting the interrogation signal It is an object of the present invention to provide an electromagnetic induction type automatic recognition device that appropriately secures the generated magnetic field strength of an interrogator and maintains good response signal reception performance of the interrogator within a target communicable distance. .
【００２１】[0021]
【課題を解決するための手段】上記目的を達成するた
め、請求項１及び４に記載の発明によれば、放出手段
が、質問信号の内容に応じ制御手段により制御されて、
質問用アンテナコイルと共振用コンデンサからなる共振
回路の交互共振中における直列共振から並列共振への移
行時毎に、当該共振回路の残留共振エネルギーを急峻に
放出し、この放出を、次の直列共振への移行時毎に停止
する。According to the first and fourth aspects of the present invention, the emission means is controlled by the control means in accordance with the content of the interrogation signal.
Every time the resonance circuit consisting of the interrogation antenna coil and the resonance capacitor shifts from the series resonance to the parallel resonance during the alternate resonance, the residual resonance energy of the resonance circuit is rapidly released, and this release is transmitted to the next series resonance. Stop every time when the transition to.
【００２２】これにより、交互共振中における直列共振
から並列共振への移行時毎の上記残留共振エネルギーの
急峻な放出のため、質問信号がその内容を変化させるこ
となく質問用アンテナコイルの発生磁界を媒体として送
信される。従って、応答器は、質問信号の正しい内容に
合致した応答信号を返信できる。また、上記残留共振エ
ネルギーの急峻な放出が次の直列共振への移行以前毎に
停止されるので、共振回路の交互共振終了後における質
問器の応答信号受信時には共振回路が確実に並列共振状
態におかれる。このため、質問器の受信性能を損なうこ
となく応答信号の良好な受信が可能となる。Thus, the steep emission of the residual resonance energy at each transition from the series resonance to the parallel resonance during the alternating resonance causes the interrogation signal to reduce the magnetic field generated by the interrogation antenna coil without changing its content. Sent as a medium. Therefore, the transponder can return a response signal that matches the correct content of the interrogation signal. In addition, since the steep emission of the residual resonance energy is stopped every time before the transition to the next series resonance, when the interrogator receives the response signal after the end of the alternate resonance of the resonance circuit, the resonance circuit surely enters the parallel resonance state. I will put it. For this reason, it is possible to excellently receive the response signal without impairing the reception performance of the interrogator.
【００２３】また、請求項２乃至５に記載の発明によれ
ば、制御手段のインピーダンス素子が、共振回路の交互
共振時にはこの共振回路に直列に接続され、当該共振回
路の並列共振の維持時にはこの共振回路から遮断され
る。これにより、インピーダンス素子の値を適正に設定
することで、インピーダンスが直列接続されている共振
回路の交互共振時にて質問用アンテナコイルの発生磁界
強度を良好に確保しつつ、共振回路の並列共振維持時に
は、インピーダンス素子の影響を受けることなく、応答
信号を良好に受信できる。Further, according to the present invention, the impedance element of the control means is connected in series to the resonance circuit at the time of alternate resonance of the resonance circuit, and is connected to the resonance element at the time of maintaining parallel resonance of the resonance circuit. It is cut off from the resonance circuit. Thus, by setting the value of the impedance element appropriately, the parallel resonance of the resonance circuit can be maintained while the magnetic field generated by the interrogation antenna coil can be sufficiently maintained during the alternate resonance of the resonance circuit whose impedance is connected in series. Sometimes, a response signal can be satisfactorily received without being affected by the impedance element.
【００２４】ここで、請求項３に記載の発明によれば、
放出手段が、質問信号の内容に応じ制御手段により制御
されて、共振回路の交互共振中における直列共振から並
列共振への移行時毎に当該共振回路の残留共振エネルギ
ーを放出し、この放出を、次の直列共振への移行時毎に
停止する。これにより、請求項２に記載の発明の作用効
果を達成しつつ請求項１に記載の発明の作用効果をも達
成できる。Here, according to the third aspect of the present invention,
The emission unit is controlled by the control unit in accordance with the content of the interrogation signal, and emits the residual resonance energy of the resonance circuit every time transition from the series resonance to the parallel resonance during the alternate resonance of the resonance circuit, It stops every time it shifts to the next series resonance. Thus, the function and effect of the invention of claim 1 can be achieved while achieving the function and effect of the invention of claim 2.
【００２５】[0025]
（第１実施形態）以下、本発明の第１実施形態を図１乃
至図４に基づいて説明する。図１は、車両用盗難防止装
置に本発明が適用された例を示している。この盗難防止
装置は、電磁誘導式自動認識装置を備えており、この自
動認識装置は、図１及び図２にて示すごとく、当該車両
のイグニッションキーシリンダ錠１０に設けた質問器Ｑ
と、イグニッションキー２０の把持部２１に内蔵した応
答器Ｒとにより構成されている。(First Embodiment) Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows an example in which the present invention is applied to a vehicle antitheft device. This antitheft device includes an electromagnetic induction type automatic recognition device. As shown in FIGS. 1 and 2, the automatic recognition device includes an interrogator Q provided on an ignition key cylinder lock 10 of the vehicle.
And a transponder R built in the grip portion 21 of the ignition key 20.
【００２６】なお、盗難防止装置においては、当該車両
の点火装置３０の点火或いはその禁止が、質問器Ｑの出
力に基づき電子制御装置４０（以下、ＥＣＵ４０とい
う）により制御されるようになっている。また、点火装
置３０に代えて、当該車両の燃料噴射装置の燃料噴射或
いはその禁止を質問器Ｑの出力に基づきＥＣＵ４０によ
り制御するようにしてもよい。In the anti-theft device, the ignition or prohibition of the ignition device 30 of the vehicle is controlled by an electronic control unit 40 (hereinafter referred to as ECU 40) based on the output of the interrogator Q. . Further, instead of the ignition device 30, the ECU 40 may control the fuel injection of the fuel injection device of the vehicle or the inhibition thereof based on the output of the interrogator Q.
【００２７】質問器Ｑは、図１及び図２にて示すごと
く、質問器本体５０ａと、図７にて示した質問用アンテ
ナコイル１とを備えている。なお、アンテナコイル１
は、イグニッションキーシリンダ錠１０のステアリング
ロック１１（アンテナコイル１のコアとしての役割を果
たす）に巻装されている。また、イグニッションキー２
０のキー部２２をイグニッションキーシリンダ錠１０の
キー孔部に挿入回転したときオンするキースイッチが、
イグニッションキーシリンダ錠１０内に設けられてい
る。As shown in FIGS. 1 and 2, the interrogator Q includes an interrogator body 50a and the interrogating antenna coil 1 shown in FIG. The antenna coil 1
Is wound around a steering lock 11 (which functions as a core of the antenna coil 1) of the ignition key cylinder lock 10. In addition, ignition key 2
The key switch that is turned on when the key portion 22 of the key 0 is inserted into the key hole portion of the ignition key cylinder lock 10 and rotated,
It is provided in the ignition key cylinder lock 10.
【００２８】質問器本体５０ａは、図２にて示すごと
く、図７にて示した質問器におけるアンテナコイル１を
除いた構成において、スイッチング回路５１を付加した
構成を有している。ここで、制御回路３は、上記キース
イッチのオン作動に応答して作動を開始し、制御信号を
発生するとともに、質問器本体５０ａの出力に基づき点
火回路３０ａの点火の可否を判定し、この判定結果をＥ
ＣＵ４０に出力する。As shown in FIG. 2, the interrogator body 50a has a configuration in which the switching circuit 51 is added to the configuration of the interrogator shown in FIG. Here, the control circuit 3 starts operating in response to the ON operation of the key switch, generates a control signal, and determines whether ignition of the ignition circuit 30a is possible based on the output of the interrogator main body 50a. The judgment result is E
Output to CU40.
【００２９】スイッチング回路５１は、Ｎチャンネル型
ＦＥＴ５１ａと、ダイオード５１ｂとを備えている。Ｆ
ＥＴ５１ａは、そのゲート端子にて、制御回路３に送信
回路４と共に接続されており、このＦＥＴ５１ａのドレ
イン端子は、ダイオード５１ｂのカソードに接続されて
いる。また、ＦＥＴ５１ａのソース端子は接地されてい
る。ダイオード５１ｂは、そのアノードにてアンテナコ
イル１とコンデンサ２の共通端子１ａに接続されてい
る。The switching circuit 51 includes an N-channel FET 51a and a diode 51b. F
The ET 51a is connected at its gate terminal to the control circuit 3 together with the transmission circuit 4, and the drain terminal of this FET 51a is connected to the cathode of the diode 51b. The source terminal of the FET 51a is grounded. The diode 51b has its anode connected to the common terminal 1a of the antenna coil 1 and the capacitor 2.
【００３０】このように構成したスイッチング回路５１
では、制御回路３からの制御信号がローレベルのとき、
ＦＥＴ５１ａはオフする。一方、制御回路３からの制御
信号がハイレベルのとき、ＦＥＴ５１ａはオンし、ダイ
オード５１ｂのカソードを接地する。ダイオード５１ｂ
は、ＦＥＴ５１ａのオフにより逆方向にバイアスされて
非導通となり、ＦＥＴ５１ａのオンにより順方向にバイ
アスされて導通する。The switching circuit 51 thus configured
Then, when the control signal from the control circuit 3 is at a low level,
The FET 51a turns off. On the other hand, when the control signal from the control circuit 3 is at a high level, the FET 51a is turned on, and the cathode of the diode 51b is grounded. Diode 51b
Is biased in the reverse direction when the FET 51a is turned off and becomes non-conductive, and is turned on and turned on when the FET 51a is turned on.
【００３１】また、アンテナコイル１とコンデンサ２と
の共通端子１ａの共振電圧がダイオード５１ｂの順方向
電圧よりも低下したときダイオード５１ｂはオフする。
応答器Ｒは、上記従来技術にて述べた応答器に代わるも
ので、応答器Ｒは、図３にて示すごとく、応答用アンテ
ナコイル６１と、このアンテナコイル６１内に同心的に
嵌装したフェライト等の強磁性体からなる棒状コア６２
と、両コンデンサ６３、６４と、電源回路６５、制御回
路６６と、復調回路６７とを備えている。When the resonance voltage of the common terminal 1a of the antenna coil 1 and the capacitor 2 becomes lower than the forward voltage of the diode 51b, the diode 51b turns off.
The transponder R is an alternative to the transponder described in the above-mentioned prior art. As shown in FIG. 3, the transponder R is fitted concentrically with a response antenna coil 61 in the antenna coil 61. Rod-shaped core 62 made of ferromagnetic material such as ferrite
, Capacitors 63 and 64, a power supply circuit 65, a control circuit 66, and a demodulation circuit 67.
【００３２】アンテナコイル６１は、質問用アンテナコ
イル１との間で磁界による電磁結合作用を発揮する。コ
ンデンサ６３はアンテナコイル６１と共に共振回路を構
成する。電源回路６５は、アンテナコイル６１とコンデ
ンサ６３との共振時にアンテナコイル６１に生ずる共振
電圧を整流するとともにこの整流電圧をチャージアップ
コンデンサに印加してこれを充電する。The antenna coil 61 exerts an electromagnetic coupling action with the interrogating antenna coil 1 by a magnetic field. The capacitor 63 forms a resonance circuit with the antenna coil 61. The power supply circuit 65 rectifies a resonance voltage generated in the antenna coil 61 when the antenna coil 61 and the capacitor 63 resonate, and applies the rectified voltage to a charge-up capacitor to charge the capacitor.
【００３３】復調回路６７は、電源回路６５から充電電
圧を受けて、ＩＤコードを応答信号として生成する。こ
こで、応答信号の生成は、上記充電電圧（アンテナコイ
ル６１の受信磁界強度に対応）が閾値よりも低下したこ
とでなされる。制御回路６６は、復調回路６７からの応
答信号にＦＭ変調をかけてアンテナコイル６１に出力す
る。The demodulation circuit 67 receives the charging voltage from the power supply circuit 65 and generates an ID code as a response signal. Here, the generation of the response signal is performed when the charging voltage (corresponding to the reception magnetic field strength of the antenna coil 61) falls below a threshold. The control circuit 66 performs FM modulation on the response signal from the demodulation circuit 67 and outputs the response signal to the antenna coil 61.
【００３４】アンテナコイル６１は、制御回路６６の出
力に基づきコンデンサ６３と共に共振し磁界を媒体とし
て応答信号を返信する。以上のように構成した本第１実
施形態において、イグニッションキーシリンダ錠１０に
イグニッションキー２０を挿入すると、制御回路３が作
動を開始し制御信号を発生する。The antenna coil 61 resonates with the capacitor 63 based on the output of the control circuit 66, and returns a response signal using a magnetic field as a medium. In the first embodiment configured as described above, when the ignition key 20 is inserted into the ignition key cylinder lock 10, the control circuit 3 starts operating and generates a control signal.
【００３５】これに伴い、質問器Ｑが応答器Ｒに電力供
給するために上記従来技術にて述べたと同様にチャージ
期間における時分割作動を行う。このとき、制御回路３
の制御信号Ａはローレベルに維持されているから、スイ
ッチング回路５１のＦＥＴ５１ａはオフしたままであ
る。このため、スイッチング回路５１がアンテナコイル
１とコンデンサ２との直列共振に悪影響を与えることは
ない。Accordingly, the interrogator Q performs a time-sharing operation in the charging period in order to supply power to the transponder R in the same manner as described in the related art. At this time, the control circuit 3
Since the control signal A is maintained at the low level, the FET 51a of the switching circuit 51 remains off. Therefore, the switching circuit 51 does not adversely affect the series resonance of the antenna coil 1 and the capacitor 2.
【００３６】その後、質問器Ｑの時分割作動が、上記従
来技術にて述べたと同様に質問信号送信期間における動
作に移行する。この質問信号送信期間では、制御回路３
が制御信号Ａ１を発生すると、この制御信号Ａ１が送信
回路４に加えスイッチング回路５１にも出力される。こ
のため、駆動回路５が従来技術にて述べたようにアンテ
ナコイル１とコンデンサ２との共振状態を直列共振から
並列共振に移行する毎に、スイッチング回路５１のＦＥ
Ｔ５１ａがオンしてダイオード５１ｂのカソードを接地
する。After that, the time-sharing operation of the interrogator Q shifts to the operation in the interrogation signal transmission period in the same manner as described in the prior art. In this interrogation signal transmission period, the control circuit 3
Generates the control signal A1, the control signal A1 is output to the switching circuit 51 in addition to the transmission circuit 4. Therefore, each time the drive circuit 5 changes the resonance state of the antenna coil 1 and the capacitor 2 from series resonance to parallel resonance as described in the related art, the FE of the switching circuit 51 is changed.
T51a is turned on, and the cathode of the diode 51b is grounded.
【００３７】これに伴い、ダイオード５１ｂが繰り返し
順方向に導通しアンテナコイル１とコンデンサ２との共
通端子１ａを接地する。このため、各直列共振の停止直
前にアンテナコイル１とコンデンサ２の共振回路に蓄え
られていた直列共振に基づく共振振動エネルギーが共振
電流としてダイオード５１ｂを通り急峻に接地側に放出
される。このことは、上記共通端子１ａの共振電圧がダ
イオード５１ｂの順方向電圧まで急峻に低下することを
意味する。Accordingly, the diode 51b repeatedly conducts in the forward direction, and the common terminal 1a of the antenna coil 1 and the capacitor 2 is grounded. Therefore, the resonance vibration energy based on the series resonance stored in the resonance circuit of the antenna coil 1 and the capacitor 2 immediately before the stop of each series resonance is rapidly discharged to the ground side through the diode 51b as a resonance current. This means that the resonance voltage of the common terminal 1a drops sharply to the forward voltage of the diode 51b.
【００３８】そして、上記共通端子１ａの共振電圧がダ
イオード５１ｂの順方向電圧よりも低下すると、ダイオ
ード５１ｂがオフする。これにより、スイッチング回路
５１が、当該ダイオード５１ｂのオフ毎に上記共通端子
１ａから電気的に遮断される。次の応答信号受信期間で
は、制御回路３が制御信号Ａ２を発生すると、この制御
信号Ａ２が送信回路４に加えスイッチング回路５１にも
出力される。このため、駆動回路５が従来技術にて述べ
たようにアンテナコイル１とコンデンサ２との共振状態
を並列共振に維持する。When the resonance voltage of the common terminal 1a falls below the forward voltage of the diode 51b, the diode 51b turns off. Thus, the switching circuit 51 is electrically disconnected from the common terminal 1a every time the diode 51b is turned off. In the next response signal receiving period, when the control circuit 3 generates the control signal A2, the control signal A2 is output to the switching circuit 51 in addition to the transmission circuit 4. Therefore, the drive circuit 5 maintains the resonance state of the antenna coil 1 and the capacitor 2 in parallel resonance as described in the related art.
【００３９】このとき、質問信号送信期間の終了時に
は、上述のごとく、共振電圧がダイオード５１ｂの順方
向電圧よりも低下することでダイオード５１ｂがオフ
し、スイッチング回路５１が共通端子１ａから遮断され
ている。このため、アンテナコイル１とコンデンサ２の
上記並列共振状態が、応答信号受信期間の初期には、ス
イッチング回路５１により影響されることなく、正常に
維持され得る。At this time, at the end of the interrogation signal transmission period, as described above, the resonance voltage falls below the forward voltage of the diode 51b, so that the diode 51b is turned off, and the switching circuit 51 is cut off from the common terminal 1a. I have. Therefore, the parallel resonance state of the antenna coil 1 and the capacitor 2 can be normally maintained without being affected by the switching circuit 51 at the beginning of the response signal receiving period.
【００４０】これにより、応答信号受信期間におけるア
ンテナコイル１による応答信号の受信及び復調処理が適
正になされ得る。 （第２実施形態）次に、本発明の第２実施形態を図５及
び図６に基づいて説明する。この第２実施形態では、上
記第１実施形態にて述べた質問器Ｑの質問器本体５０ａ
において、スイッチング回路５１を廃止するとともに、
質問器Ｑの質問信号を応答器Ｒに確実に伝達するため
に、直流電源の正側端子とＦＥＴ５ｂのソース端子との
間に抵抗５２を接続したことにその構成上の特徴があ
る。Thus, reception and demodulation of the response signal by the antenna coil 1 during the response signal reception period can be properly performed. (Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIGS. In the second embodiment, the interrogator main body 50a of the interrogator Q described in the first embodiment is described.
In addition to eliminating the switching circuit 51,
In order to reliably transmit the interrogation signal of the interrogator Q to the transponder R, the configuration is characterized in that the resistor 52 is connected between the positive terminal of the DC power supply and the source terminal of the FET 5b.
【００４１】ここで、抵抗５２の抵抗値は、応答器Ｒが
目標通信距離以内でアンテナコイル１の発生磁界の変化
を良好に検出できる程度に選定されている。その他の構
成は、上記第１実施形態と同様である。このように構成
した本第２実施形態では、上記第１実施形態と同様に質
問器Ｑが応答器Ｒに電力供給するために上記従来技術に
て述べたと同様にチャージ期間における時分割作動を行
うと、駆動回路５には抵抗５２が上述のごとく接続され
ているから、ＦＥＴ５ａ又は５ｂのオン作動に伴いアン
テナコイル１及びコンデンサ２に流れる電流量は、上記
直流電圧Ｖｃから抵抗５２の電圧降下分を除いた電圧に
より特定される。Here, the resistance value of the resistor 52 is selected so that the transponder R can properly detect a change in the magnetic field generated by the antenna coil 1 within the target communication distance. Other configurations are the same as those in the first embodiment. In the second embodiment configured as described above, the interrogator Q performs the time-sharing operation in the charging period in the same manner as described in the related art in order to supply the power to the transponder R in the same manner as in the first embodiment. Since the resistor 52 is connected to the drive circuit 5 as described above, the amount of current flowing through the antenna coil 1 and the capacitor 2 when the FET 5a or 5b is turned on is reduced by the voltage drop of the resistor 52 from the DC voltage Vc. Is specified by the voltage excluding.
【００４２】このため、アンテナコイル１の端子電圧に
生ずる電圧は、図６にて符号Ｃ’にて示すごとく、図８
の場合よりも低くなる。しかし、抵抗５２の抵抗値は、
上述のごとく、応答器Ｒがアンテナコイル１の発生磁界
の変化を良好に検出できる程度に選定されているため、
応答器Ｒのアンテナコイル６１の受信磁界強度が目標通
信距離以内で不足することがない。For this reason, the voltage generated at the terminal voltage of the antenna coil 1 is, as shown by reference numeral C ′ in FIG.
Lower than in the case of However, the resistance value of the resistor 52 is
As described above, since the transponder R is selected so that the change in the magnetic field generated by the antenna coil 1 can be detected satisfactorily,
The received magnetic field strength of the antenna coil 61 of the transponder R does not become insufficient within the target communication distance.
【００４３】また、質問信号送信期間でも、アンテナコ
イル１の端子電圧に生ずる電圧は、図８にて符号Ｃ１”
にて示すごとく、チャージ期間と同様に小さくなるが、
このときも、同様にアンテナコイル６１の受信磁界強度
が良好に維持される（図８にて符号Ｄ１”参照）。続く
応答信号受信期間では、ＦＥＴ５ａのオンにより、アン
テナコイル１とコンデンサ２が、その共通端子１ａに
て、接地されて並列共振する。Also, during the interrogation signal transmission period, the voltage generated at the terminal voltage of the antenna coil 1 is the same as the voltage C1 ″ in FIG.
As shown by, it becomes smaller like the charge period,
Also at this time, similarly, the reception magnetic field strength of the antenna coil 61 is favorably maintained (see D1 ″ in FIG. 8). In the subsequent response signal reception period, the FET 5a is turned on, so that the antenna coil 1 and the capacitor 2 are connected. The common terminal 1a is grounded and resonates in parallel.
【００４４】このとき、上述のごとく、抵抗５２が直流
電源の正側端子とＦＥＴ５ｂのソース端子との間に接続
されているから、ＦＥＴ５ｂのオフのもと、共通端子１
ａの接地は、抵抗５２を介することなくなされる。この
ため、アンテナコイル１とコンデンサ２の並列共振が抵
抗５２に影響されることなく正常に維持される。その結
果、質問器Ｑのアンテナコイル１における受信性能を良
好に維持できる。また、当該車両のイグニッションキー
２０に他車のイグニッションキーをキーホルダーにより
付帯してある場合でも、イグニッションキー２０をイグ
ニッションキーシリンダ１０に差し込んだ状態において
は、付帯したイグニッションキーの応答器とアンテナコ
イル１との距離が上記目標通信距離内にない。このた
め、付帯したイグニッションキーの応答器との間で質問
器Ｑとの混信が生ずることもない。At this time, as described above, the resistor 52 is connected between the positive terminal of the DC power supply and the source terminal of the FET 5b.
The grounding of “a” is performed without passing through the resistor 52. Therefore, the parallel resonance of the antenna coil 1 and the capacitor 2 is normally maintained without being affected by the resistor 52. As a result, the reception performance of the interrogator Q at the antenna coil 1 can be maintained satisfactorily. Further, even when the ignition key of the other vehicle is attached to the ignition key 20 of the other vehicle by a key holder, when the ignition key 20 is inserted into the ignition key cylinder 10, the transponder of the attached ignition key and the antenna coil 1 are attached. Is not within the target communication distance. Therefore, there is no occurrence of interference with the interrogator Q between the attached ignition key and the transponder.
【００４５】なお、本発明の実施にあたり、駆動回路や
スイッチング回路では、ＦＥＴに代えて、例えば、バイ
ポーラトランジスタやアナログスイッチを採用して実施
してもよい。本発明の実施にあたり、上記第１実施形態
にて述べた質問器Ｑにおいて、上記第２実施形態にて述
べた抵抗５２を、直流電源の正側端子とＦＥＴ５ｂのソ
ース端子との間に接続して実施にてもよい。In implementing the present invention, the drive circuit and the switching circuit may be implemented by using, for example, a bipolar transistor or an analog switch instead of the FET. In implementing the present invention, in the interrogator Q described in the first embodiment, the resistor 52 described in the second embodiment is connected between the positive terminal of the DC power supply and the source terminal of the FET 5b. May be implemented.
【００４６】これにより、上記第１及び第２の実施形態
の両作用効果を合わせて達成することが可能となる。ま
た、本発明の実施にあたり、車両用盗難防止装置に限る
ことなく、固定局と移動局を有する無線による移動局識
別装置等にも本発明を適用して実施してもよい。Thus, it is possible to achieve both the effects of the first and second embodiments. In practicing the present invention, the present invention is not limited to a vehicle anti-theft device, but may be applied to a wireless mobile station identification device having a fixed station and a mobile station.
【図１】本発明の一実施形態を示す概略全体構成図であ
る。FIG. 1 is a schematic overall configuration diagram showing an embodiment of the present invention.
【図２】図１の質問器Ｑの回路構成図である。FIG. 2 is a circuit configuration diagram of an interrogator Q of FIG. 1;
【図３】図１の応答器Ｒの回路構成図である。FIG. 3 is a circuit configuration diagram of a transponder R of FIG. 1;
【図４】質問器Ｑ及び応答器Ｒのチャージ期間、質問信
号送信期間及び応答信号受信期間における主要構成素子
の出力動作波形図である。FIG. 4 is an output operation waveform diagram of main components in a charging period, an interrogation signal transmission period, and a response signal reception period of the interrogator Q and the transponder R.
【図５】本発明の第２実施形態を示す要部回路図であ
る。FIG. 5 is a main part circuit diagram showing a second embodiment of the present invention.
【図６】上記第２実施形態における質問器Ｑ及び応答器
Ｒのチャージ期間、質問信号送信期間及び応答信号受信
期間における主要構成素子の出力動作波形図である。FIG. 6 is an output operation waveform diagram of main constituent elements in a charging period, an interrogation signal transmission period, and a response signal reception period of the interrogator Q and the transponder R in the second embodiment.
【図７】従来の質問器の回路構成図である。FIG. 7 is a circuit configuration diagram of a conventional interrogator.
【図８】図７の質問器及びその応答器のチャージ期間、
質問信号送信期間及び応答信号受信期間における主要構
成素子の出力動作波形図である。8 is a charge period of the interrogator and its transponder of FIG. 7,
FIG. 8 is an output operation waveform diagram of a main component element during an interrogation signal transmission period and a response signal reception period.
Ｑ…質問器、Ｒ…応答器、１…質問用アンテナコイル、
２…共振用コンデンサ、３…制御回路、４…送信回路、
５…駆動回路、５０ａ…質問器本体、５１…スイッチン
グ回路、５１ａ…ＦＥＴ、５１ｂ…ダイオード、５２…
抵抗。Q: Interrogator, R: Answerer, 1 ... Antenna coil for interrogation,
2 ... resonance capacitor, 3 ... control circuit, 4 ... transmission circuit,
5 ... Drive circuit, 50a ... Interrogator main body, 51 ... Switching circuit, 51a ... FET, 51b ... Diode, 52 ...
resistance.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 水野 耕一 愛知県刈谷市昭和町１丁目１番地 株式会 社デンソー内 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Koichi Mizuno 1-1-1, Showa-cho, Kariya-shi, Aichi Pref.
Claims (5)
ンデンサ（２）とからなる共振回路と、 質問信号の内容に応じて並列共振及び直列共振を交互に
繰り返す交互共振をするように前記共振回路を制御した
後この共振回路を並列共振に維持するように制御する制
御手段（３、４、５）とを備え、 前記共振回路の交互共振に基づき前記質問用アンテナコ
イルら生ずる質問用磁界を媒体として前記質問信号を送
信する質問器（Ｑ）と、 前記送信質問信号を受信することにより応答信号を応答
用磁界を媒体として返信する応答器（Ｒ）とを設けて、 前記質問器が、前記共振回路の並列共振の維持に基づき
前記質問用アンテナコイルにより前記応答信号を受信す
るようにした電磁誘導式自動認識装置において、 前記質問信号の内容に応じ前記制御手段により制御され
て前記共振回路の交互共振中における直列共振から並列
共振への移行時毎に当該共振回路の残留共振エネルギー
を急峻に放出し、この放出を、次の直列共振への移行以
前毎に停止する放出手段（５１）を具備する電磁誘導式
自動認識装置。1. A resonance circuit comprising an interrogation antenna coil (1) and a resonance capacitor (2), and said resonance circuit performing alternate resonance that alternately repeats parallel resonance and series resonance according to the content of an interrogation signal. Control means (3, 4, 5) for controlling the resonance circuit so as to maintain parallel resonance after controlling the circuit, wherein the interrogation magnetic field generated from the interrogation antenna coil based on the alternate resonance of the resonance circuit is provided. An interrogator (Q) that transmits the interrogation signal as a medium, and a transponder (R) that receives the transmission interrogation signal and returns a response signal using a response magnetic field as a medium, wherein the interrogator comprises: In the electromagnetic induction type automatic recognition device configured to receive the response signal by the interrogation antenna coil based on maintaining parallel resonance of the resonance circuit, the control may be performed according to the content of the interrogation signal. Controlled by the stage, each time the resonance circuit shifts from series resonance to parallel resonance during the alternate resonance, the residual resonance energy of the resonance circuit is rapidly released, and this release is performed every time before the transition to the next series resonance. An electromagnetic induction type automatic recognition device comprising a discharge means (51) that stops at a predetermined time.
ンデンサ（２）とからなる共振回路と、 質問信号の内容に応じて並列共振及び直列共振を交互に
繰り返す交互共振をするように前記共振回路を制御した
後この共振回路を並列共振に維持するように制御する制
御手段（３、４、５）とを備え、 前記共振回路の交互共振に基づき前記質問用アンテナコ
イルら生ずる質問用磁界を媒体として前記質問信号を送
信する質問器（Ｑ）と、 前記送信質問信号を受信することにより応答信号を応答
用磁界を媒体として返信する応答器（Ｒ）とを設けて、 前記質問器が、前記共振回路の並列共振の維持に基づき
前記質問用アンテナコイルにより前記応答信号を受信す
るようにした電磁誘導式自動認識装置において、 前記制御手段が、前記共振回路の交互共振時にはこの共
振回路に直列に接続され、当該共振回路の並列共振の維
持時にはこの共振回路から遮断されるインピーダンス素
子（５２）を備えることを特徴とする電磁誘導式自動認
識装置。2. A resonance circuit comprising an interrogation antenna coil (1) and a resonance capacitor (2), and said resonance circuit performing alternate resonance in which parallel resonance and series resonance are alternately repeated according to the content of an interrogation signal. Control means (3, 4, 5) for controlling the resonance circuit so as to maintain parallel resonance after controlling the circuit, wherein the interrogation magnetic field generated from the interrogation antenna coil based on the alternate resonance of the resonance circuit is provided. An interrogator (Q) that transmits the interrogation signal as a medium, and a transponder (R) that receives the transmission interrogation signal and returns a response signal using a response magnetic field as a medium, wherein the interrogator comprises: In the electromagnetic induction type automatic recognition device configured to receive the response signal by the interrogating antenna coil based on maintenance of parallel resonance of the resonance circuit, the control unit may switch the resonance circuit. The time of resonance is connected to the resonant circuit in series, an electromagnetic induction type automatic recognition device during maintenance of the parallel resonance of the resonant circuit, characterized in that it comprises an impedance element to be cut off from the resonant circuit (52).
により制御されて前記共振回路の交互共振中における直
列共振から並列共振への移行時毎に当該共振回路の残留
共振エネルギーを急峻に放出し、この放出を、次の直列
共振への移行以前毎に停止する放出手段（５１）を備え
る請求項２に記載の電磁誘導式自動認識装置。3. The residual resonance energy of the resonance circuit is sharply released every time the resonance circuit shifts from series resonance to parallel resonance during alternate resonance of the resonance circuit under the control of the control means in accordance with the content of the interrogation signal. The electromagnetic induction type automatic recognition device according to claim 2, further comprising emission means (51) for stopping the emission before the transition to the next series resonance.
て前記共振回路の交互共振中における直列共振から並列
共振への移行時毎に導通するスイッチング素子（５１
ａ）と、 このスイッチング素子の導通毎に順方向にバイアスされ
て当該共振回路の残留共振エネルギーを前記スイッチン
グ素子を通して急峻に放出するダイオード（５１ｂ）と
を備え、 前記交互共振における並列共振から直列共振への各移行
以前に前記残留エネルギーに対応する共振電圧が前記ダ
イオードの順方向電圧より低下することで当該ダイオー
ドが前記残留エネルギーの放出を停止するようにしたこ
とを特徴とする請求項１又は３に記載のに記載の電磁誘
導式自動認識装置。4. A switching element (51) controlled by said control means in accordance with the contents of said interrogation signal, said emission means being turned on each time said resonance circuit shifts from series resonance to parallel resonance.
a) and a diode (51b) that is biased in a forward direction each time the switching element is turned on and rapidly discharges the residual resonance energy of the resonance circuit through the switching element. 4. The diode stops emission of the residual energy when the resonance voltage corresponding to the residual energy becomes lower than the forward voltage of the diode before each transition to (b). 5. The electromagnetic induction type automatic recognition device according to any one of the above.
応じて前記交互共振をするように前記共振回路を駆動す
る駆動回路（５）を備えており、 前記インピーダンス素子が、前記交互共振時には前記駆
動回路を通し前記共振回路に直列接続されこの共振回路
からその並列共振の維持時に前記駆動回路により遮断さ
れる抵抗であることを特徴とする請求項２又は３に記載
の電磁誘導式自動認識装置。5. The control means includes a drive circuit (5) for driving the resonance circuit so as to perform the alternate resonance in accordance with the content of the interrogation signal. 4. The electromagnetic induction type automatic recognition according to claim 2, wherein the resistor is connected in series to the resonance circuit through the drive circuit, and is disconnected from the resonance circuit by the drive circuit when the parallel resonance is maintained. 5. apparatus.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2414997A JP3564917B2 (en) | 1997-02-06 | 1997-02-06 | Electromagnetic induction type automatic recognition device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2414997A JP3564917B2 (en) | 1997-02-06 | 1997-02-06 | Electromagnetic induction type automatic recognition device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH10224276A true JPH10224276A (en) | 1998-08-21 |
| JP3564917B2 JP3564917B2 (en) | 2004-09-15 |
Family
ID=12130288
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2414997A Expired - Fee Related JP3564917B2 (en) | 1997-02-06 | 1997-02-06 | Electromagnetic induction type automatic recognition device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3564917B2 (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1538036A1 (en) * | 2003-12-04 | 2005-06-08 | Alps Electric Co., Ltd. | Passive keyless entry device |
| WO2006030493A1 (en) * | 2004-09-14 | 2006-03-23 | Mitsubishi Denki Kabushiki Kaisha | Non-contact type communication system |
| EP1705082A2 (en) | 2005-03-24 | 2006-09-27 | Alps Electric Co., Ltd. | Passive keyless entry device |
| JP2009135859A (en) * | 2007-12-03 | 2009-06-18 | Panasonic Corp | Antenna device |
| KR100959237B1 (en) | 2007-07-12 | 2010-05-19 | 오므론 가부시키가이샤 | Transmission device and methode |
-
1997
- 1997-02-06 JP JP2414997A patent/JP3564917B2/en not_active Expired - Fee Related
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1538036A1 (en) * | 2003-12-04 | 2005-06-08 | Alps Electric Co., Ltd. | Passive keyless entry device |
| WO2006030493A1 (en) * | 2004-09-14 | 2006-03-23 | Mitsubishi Denki Kabushiki Kaisha | Non-contact type communication system |
| EP1705082A2 (en) | 2005-03-24 | 2006-09-27 | Alps Electric Co., Ltd. | Passive keyless entry device |
| EP1705082A3 (en) * | 2005-03-24 | 2008-12-03 | Alps Electric Co., Ltd. | Passive keyless entry device |
| KR100959237B1 (en) | 2007-07-12 | 2010-05-19 | 오므론 가부시키가이샤 | Transmission device and methode |
| JP2009135859A (en) * | 2007-12-03 | 2009-06-18 | Panasonic Corp | Antenna device |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3564917B2 (en) | 2004-09-15 |
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