JPH11338983A - Reader-writer for non-contact ic card, and output power control method therefor - Google Patents
Reader-writer for non-contact ic card, and output power control method thereforInfo
- Publication number
- JPH11338983A JPH11338983A JP10139833A JP13983398A JPH11338983A JP H11338983 A JPH11338983 A JP H11338983A JP 10139833 A JP10139833 A JP 10139833A JP 13983398 A JP13983398 A JP 13983398A JP H11338983 A JPH11338983 A JP H11338983A
- Authority
- JP
- Japan
- Prior art keywords
- card
- contact
- antenna
- voltage
- coupling coefficient
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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- Continuous-Control Power Sources That Use Transistors (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、非接触ＩＣカード
用リーダ／ライタ装置に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reader / writer for a non-contact IC card.
【０００２】[0002]
【従来の技術】非接触ＩＣカードは、ＩＣカード内に電
源を持たず、リーダ／ライタ装置から電磁結合により電
力が供給され、その電力で動作する。また、データ通信
も同じ電磁結合により非接触で行われる。図８は、リー
ダ／ライタ装置側の電力供給部と、非接触ＩＣカード側
の受電系統を示したもので、発振器１から出力された周
波数ｆｃの高周波が増幅器２で増幅され、整合回路３を
介して自己インダクタンスＬ１のアンテナコイルへ供給
される。このアンテナコイルには、伝送効率を上げるた
め、容量Ｃ１の同調コンデンサが直接接続されている。
図中Ｒ１はこのアンテナコイルの損失抵抗を表してい
る。2. Description of the Related Art A non-contact IC card does not have a power supply in the IC card, but is supplied with power from a reader / writer device by electromagnetic coupling, and operates with the power. Also, data communication is performed in a non-contact manner by the same electromagnetic coupling. FIG. 8 shows a power supply unit on the reader / writer device side and a power receiving system on the non-contact IC card side. Is supplied to the antenna coil of the self-inductance L1 via the antenna coil. A tuning capacitor having a capacitance C1 is directly connected to the antenna coil to increase transmission efficiency.
In the figure, R1 represents the loss resistance of the antenna coil.
【０００３】非接触ＩＣカード側のアンテナコイルにも
同調コンデンサＣ２が並列接続されており、自己インダ
クタンスＬ２と共振して伝送効率を高めるようにしてい
る。この非接触ＩＣカード側のアンテナコイルがリーダ
／ライタ装置側のアンテナコイルと電磁結合すると誘起
電圧が発生し、これがダイオード回路４で整流され、レ
ギュレータ５で所定の電圧に調整され、ＩＣ回路６へ供
給される。[0003] A tuning capacitor C2 is also connected in parallel to the antenna coil on the non-contact IC card side to resonate with the self-inductance L2 to increase the transmission efficiency. When the antenna coil on the non-contact IC card side is electromagnetically coupled with the antenna coil on the reader / writer device side, an induced voltage is generated, which is rectified by the diode circuit 4, adjusted to a predetermined voltage by the regulator 5, and sent to the IC circuit 6. Supplied.
【０００４】[0004]
【発明が解決しようとする課題】非接触ＩＣカードで
は、リーダ／ライタ装置のアンテナコイルからＩＣカー
ドが動作可能な距離の範囲が決められており、その動作
範囲の中では電力を最も多く受電する位置と最も少ない
電力を受電する位置があり、この動作範囲内で受電する
電力に差がある。そして非接触ＩＣカードが動作範囲内
で安定するためには、最も少ない電力を受電する位置で
非接触ＩＣカードが動作するために必要な電力を受電で
きるように、リーダ／ライタ装置の出力が設定されてい
る。従って最小の電力を受電する位置以外では、非接触
ＩＣカード内のＩＣ回路が必要とする電力以外のエネル
ギーは余分となり、レギュレータはこの余分の電力を熱
放散して所定の出力電圧が得られるようにしている。こ
のために非接触ＩＣカードの動作範囲内であっても、そ
の位置によってはレギュレータから発生する熱量が大き
くなり、電力を最も多く受電する位置で最大になる。こ
の際、レギュレータで発生する熱により直接ＩＣを破損
したり、その熱によりＩＣカードの形成材である合成樹
脂等が変形することによってＩＣを破損する恐れがあ
る、また、レギュレータが許容する入力電圧より大きい
電圧がかかると、レギュレータを破損してしまう恐れが
ある。特に非接触ＩＣカードがリーダ／ライタ装置の動
作範囲内に長時間放置された場合にはこうした問題が発
生しやすくなる。In a non-contact IC card, the range of the operable distance of the IC card from the antenna coil of the reader / writer device is determined, and the most power is received in the operating range. There is a position and a position that receives the least power, and there is a difference in the power received within this operating range. In order for the contactless IC card to be stable within the operating range, the output of the reader / writer device is set so that the contactless IC card can receive power required to operate at the position receiving the least power. Have been. Therefore, except for the position where the minimum power is received, the energy other than the power required by the IC circuit in the non-contact IC card becomes extra, and the regulator dissipates this extra power to obtain a predetermined output voltage. I have to. Therefore, even within the operating range of the non-contact IC card, the amount of heat generated from the regulator increases depending on the position, and becomes maximum at the position where the most power is received. At this time, there is a risk that the IC may be directly damaged by heat generated by the regulator, or the synthetic resin or the like, which is a material for forming the IC card, may be deformed by the heat. If a higher voltage is applied, the regulator may be damaged. In particular, when the non-contact IC card is left in the operation range of the reader / writer device for a long time, such a problem is likely to occur.
【０００５】本発明の目的は、非接触ＩＣカードへの過
電力伝送による発熱でＩＣを破損したり、またはレギュ
レータの過電圧による破損が生じないようにした非接触
ＩＣカード用リーダ／ライタ装置を提供することにあ
る。An object of the present invention is to provide a reader / writer device for a non-contact IC card which prevents the IC from being damaged by heat generated by over-power transmission to the non-contact IC card, or from being damaged by over-voltage of the regulator. Is to do.
【０００６】[0006]
【課題を解決するための手段】上記の目的を達成するた
めに、本発明は、非接触ＩＣカードのアンテナと自装置
のアンテナの電磁結合によって非接触ＩＣカードへ電力
を供給する機能を有したリーダ／ライタ装置であって、
自装置のアンテナへ供給する高周波供給電力を制御する
ための電力制御手段と、自装置のアンテナへの入力高周
波電圧を検出するための電圧検出手段と、該手段により
検出された入力高周波電圧と前記電力制御手段の出力電
圧とから非接触ＩＣカードのアンテナと自装置のアンテ
ナの結合係数を求めるための結合係数算出手段と、該手
段により求められた結合係数から非接触ＩＣカードの受
電電力が予め定められた値となるように前記電力制御手
段の出力電圧を制御するための制御手段と、を備えたこ
とを特徴とする非接触ＩＣカード用リーダ／ライタ装置
を提供する。In order to achieve the above object, the present invention has a function of supplying power to a non-contact IC card by electromagnetic coupling between an antenna of the non-contact IC card and an antenna of its own device. A reader / writer device,
Power control means for controlling the high-frequency supply power supplied to the antenna of the own device, voltage detecting means for detecting the input high-frequency voltage to the antenna of the own device, the input high-frequency voltage detected by the means, Coupling coefficient calculating means for calculating the coupling coefficient between the antenna of the non-contact IC card and the antenna of the own device from the output voltage of the power control means; and receiving power of the non-contact IC card from the coupling coefficient calculated by the means. And a control means for controlling an output voltage of the power control means so as to have a predetermined value. A reader / writer device for a contactless IC card is provided.
【０００７】また、本発明は、非接触ＩＣカードのアン
テナと自装置のアンテナの電磁結合によって非接触ＩＣ
カードへ電力を供給する機能を有したリーダ／ライタ装
置であって、自装置のアンテナへ供給する高周波供給電
力を制御するための電力制御手段と、自装置のアンテナ
への入力高周波電流を検出するための電流検出手段と、
該手段により検出された入力高周波電流と前記電力制御
手段の出力電圧とから非接触ＩＣカードのアンテナと自
装置のアンテナの結合係数を求めるための結合係数算出
手段と、該手段により求められた結合係数から非接触Ｉ
Ｃカードの受電電力が予め定められた値となるように前
記電力制御手段の出力電圧を制御するための制御手段
と、を備えたことを特徴とする非接触ＩＣカード用リー
ダ／ライタ装置を提供する。Further, the present invention provides a non-contact IC by electromagnetic coupling between the antenna of the non-contact IC card and the antenna of the own device.
A reader / writer device having a function of supplying power to a card, a power control means for controlling high-frequency power supplied to an antenna of the device, and a high-frequency current input to the antenna of the device. Current detection means for
Coupling coefficient calculating means for calculating a coupling coefficient between the antenna of the non-contact IC card and the antenna of the own device from the input high-frequency current detected by the means and the output voltage of the power control means; and the coupling determined by the means. Non-contact I from coefficient
A control unit for controlling the output voltage of the power control unit so that the received power of the C card becomes a predetermined value. Provided is a reader / writer device for a non-contact IC card. I do.
【０００８】また、本発明は、前記電圧検出手段または
前記電流検出手段の検出した高周波電圧または電流が予
め定めた時間以上変化しなかったときはこれを検出し、
前記電力制御手段の出力電圧を低下させる第２の制御手
段を付加したことを特徴とする非接触ＩＣカード用リー
ダ／ライタ装置を提供する。Further, the present invention detects when the high-frequency voltage or current detected by the voltage detecting means or the current detecting means has not changed for a predetermined time or more,
A non-contact IC card reader / writer device is provided, wherein a second control means for lowering the output voltage of the power control means is added.
【０００９】[0009]
【発明の実施の形態】以下、本発明の実施の形態を説明
する。図１は、本発明になるリーダ／ライタ装置の構成
例を示すブロック図で、電力伝送に関係する部分のみを
図示している。従来の図８と同一回路は同一符号で示さ
れており、それら同一符号で示された回路の他に、増幅
器２の出力高周波の電圧Ｖ（実効値）を検知するための
電圧検知回路１１と、出力電力を可変制御するための電
力制御回路１３とが付加されている。リーダ／ライタ装
置用ＩＣ１２は、従来からリーダ／ライタ装置の動作制
御を行うために設けられているものであるが、前記の電
圧検知回路１１の出力信号もこのＩＣ１２へ入力され
る。Embodiments of the present invention will be described below. FIG. 1 is a block diagram showing a configuration example of a reader / writer device according to the present invention, and shows only a portion related to power transmission. 8 are denoted by the same reference numerals, and in addition to the circuits denoted by the same reference numerals, a voltage detection circuit 11 for detecting a high-frequency voltage V (effective value) output from the amplifier 2 is provided. And a power control circuit 13 for variably controlling the output power. The reader / writer device IC 12 is conventionally provided for controlling the operation of the reader / writer device. The output signal of the voltage detection circuit 11 is also input to the IC 12.
【００１０】図２は、図１の電力伝送系統の等価回路で
ある。この等価回路で、電源２０は図２の発振器１及び
電力制御回路１３からなる回路で、その出力電圧をＶｓ
とする。周波数ｆｃ＝１３．５６ＭHz、増幅器２の出力
インピーダンスＲS＝５０Ω、リーダ／ライタ装置のア
ンテナの自己インダクタンスＬ１＝６．８μＨ、カード
アンテナの自己インダクタンスＬ２＝１．５μＨ、リー
ダ／ライタ装置のアンテナの損失Ｒ１＝１２．５Ωと
し、Ｃ１はＬ１と、Ｃ２はＬ２とそれぞれ周波数ｆｃに
共振がとれており、整合回路３はリーダ／ライタ装置の
アンテナと発信機の出力インピーダンスＲｓとの整合を
取っているものとし、さらにカードＩＣの疑似負荷であ
るＲL＝２．５６ｋΩとする。両アンテナの相互インダ
クタンスをＭとすると両アンテナの結合係数ｋはFIG. 2 is an equivalent circuit of the power transmission system of FIG. In this equivalent circuit, the power supply 20 is a circuit including the oscillator 1 and the power control circuit 13 shown in FIG.
And Frequency fc = 13.56 MHz, output impedance RS of amplifier 2 = 50 Ω, self-inductance L1 of the antenna of the reader / writer device = 6.8 µH, self-inductance L2 of the card antenna L2 = 1.5 µH, loss of the reader / writer device antenna R1 = 12.5Ω, C1 and L2 resonate at frequency fc, respectively, and C2 matches L2 with the antenna of the reader / writer device and the output impedance Rs of the transmitter. RL = 2.56 kΩ, which is a pseudo load of the card IC. If the mutual inductance of both antennas is M, the coupling coefficient k of both antennas is
【数１】ｋ＝Ｍ／（Ｌ１・Ｌ２）1/2 であるから、この結合係数ｋを与えればＭが決まる。そ
こで電源２０の出力電圧Ｖｓをパラメータとし、結合係
数ｋを０〜０．１まで、０．０１間隔で変化させた場合
の出力電圧Ｖを図２の等価回路を用いてシミュレートす
ると、図３のような結果が得られる。即ち、結合係数ｋ
が増大するにつれて増幅器２の出力電圧Ｖは増大する。
但しこのような電圧Ｖは、増幅器２の出力インピーダン
スＲｓがあまり小さいと変化が殆ど現れないが、通常は
Ｒｓ＝５０Ωあるいは７５Ωのものが用いられるので、
電圧Ｖが結合係数ｋの変化に伴って変化する。## EQU1 ## Since k = M / (L1.L2) 1/2 , M is determined by giving the coupling coefficient k. When the output voltage Vs of the power supply 20 is used as a parameter and the output voltage V when the coupling coefficient k is changed from 0 to 0.1 at intervals of 0.01 is simulated using the equivalent circuit of FIG. Is obtained. That is, the coupling coefficient k
Increases, the output voltage V of the amplifier 2 increases.
However, such a voltage V hardly changes when the output impedance Rs of the amplifier 2 is too small. However, since a voltage of Rs = 50Ω or 75Ω is usually used,
The voltage V changes as the coupling coefficient k changes.
【００１１】図３の結果から、電源２０の出力電圧、即
ち電力制御回路１３の出力電圧Ｖｓと増幅器２の出力Ｖ
が与えられと、そのときの結合係数ｋの値が一意に決ま
ることがわかる。電力制御回路１３の出力電圧ＶｓはＩ
Ｃ１２により制御されるので、ＩＣ１２にはＶｓの値は
わかっており、また電圧検知回路１１の出力信号から増
幅器２の出力電圧ＶもＩＣ１２にはわかっている。従っ
て図３のような回路特性が与えられれば、ＩＣ１２は各
時点に於ける結合係数ｋの値を知ることができる。FIG. 3 shows that the output voltage of the power supply 20, ie, the output voltage Vs of the power control circuit 13 and the output voltage V
, The value of the coupling coefficient k at that time is uniquely determined. The output voltage Vs of the power control circuit 13 is I
Since it is controlled by C12, the value of Vs is known to IC12, and the output voltage V of amplifier 2 is also known to IC12 from the output signal of voltage detection circuit 11. Therefore, given the circuit characteristics as shown in FIG. 3, the IC 12 can know the value of the coupling coefficient k at each time.
【００１２】その具体的な方法として例えば次のものが
ある。まず図３からも容易にわかるが、Ｖｓとｋの関数
である電圧ＶはＶｓの値に比例している。従ってThe following is a specific method, for example. First, as can be easily seen from FIG. 3, the voltage V, which is a function of Vs and k, is proportional to the value of Vs. Therefore
【数２】Ｖ＝Ｖｓ・ｆ（ｋ） とかける。従って例えば図３の任意のＶｓに対して各ｋ
の値にたいするｆ（ｋ）をＶ／Ｖｓから求めておけば、
この関数ｆ（ｋ）はＶｓに依存しない曲線である。そこ
でこの関数ｆ（ｋ）とＶ／Ｖｓの関数を予め等価回路を
用いて計算により求めておくか、あるいは実験的に求め
て第１テーブルとし、ＩＣ１２内のＲＯＭに格納してお
く。そうすれば各時点のＶとＶｓの値から結合係数ｋの
値をそのテーブルを参照して容易に求めることができ
る。またｆ（ｋ）の逆関数V = Vs · f (k) Therefore, for example, for each Vs in FIG.
If f (k) for the value of is determined from V / Vs,
This function f (k) is a curve independent of Vs. Therefore, the function f (k) and the function of V / Vs are obtained in advance by calculation using an equivalent circuit, or are obtained experimentally as a first table and stored in the ROM in the IC 12. Then, the value of the coupling coefficient k can be easily obtained from the values of V and Vs at each time point by referring to the table. Also, the inverse function of f (k)
【数３】ｋ＝ｆ-1（Ｖ／Ｖｓ） をテーブルではなく、理論式あるいは近似式として求
め、ＩＣ１２内のプログラムに持たせておいてもよい。[Mathematical formula-see original document] k = f -1 (V / Vs) may be obtained not as a table but as a theoretical expression or an approximate expression, and may be stored in a program in the IC 12.
【００１３】リーダ／ライタ用ＩＣ１２にはもう一つの
テーブルもしくは数式を用意する。非接触ＩＣカードの
受信電力として、カードが安定に動作し、かつ余分な熱
を放出しなくてよいような受信電力をＰ0とする。非接
触ＩＣカードの受信電力Ｐは、リーダ／ライタ装置の増
幅器２の出力電圧Ｖと結合係数ｋで決まるが、（数２）
の関係を考えるとある関数ｇがあってAnother table or mathematical formula is prepared in the reader / writer IC 12. As the received power of the non-contact IC card, P0 is the received power at which the card operates stably and does not need to emit extra heat. The received power P of the contactless IC card is determined by the output voltage V of the amplifier 2 of the reader / writer device and the coupling coefficient k.
Given a relationship, there is a function g
【数４】Ｐ＝ｇ（Ｖｓ，ｋ） とかける。従って## EQU4 ## P = g (Vs, k). Therefore
【数５】Ｐ0＝ｇ（Ｖｓ，ｋ） となるＶｓとｋの関係を予め求めて第２テーブルとして
ＩＣ１２内のＲＯＭに格納しておく。それもテーブルで
はなく近似関数で表しておいてもよい。## EQU5 ## The relationship between Vs and k that satisfies P0 = g (Vs, k) is obtained in advance and stored in the ROM in the IC 12 as a second table. It may be represented by an approximate function instead of a table.
【００１４】リーダ／ライタ用ＩＣ１２は、以上の第１
及び第２テーブルを利用して図４に示したフローに従っ
て送信電力の制御を行う。同図において、まず電力制御
回路１３の出力電圧Ｖｓの設定値を初期化する（ステッ
プ４１）。このときの初期値は適当に定めればよく、例
えば（数４）でｋ＝０．０５のときのＶｓ値とする。次
に電力制御回路１３へ制御信号を出力してその出力電圧
が初期化した設定値Ｖｓとなるようにし（ステップ４
２）、制御タイミングを待つ（ステップ４３）。制御タ
イミングになると電圧検知回路１１の出力信号を取り込
んで増幅器２の出力電圧Ｖを求め（ステップ４４）、次
いで前記した第１テーブルからＶ／Ｖｓに対する結合係
数ｋを求める（ステップ４５）。そしてその求めた結合
係数ｋに対するＶｓの値を第２テーブルから求め（ステ
ップ４６）、ステップ４２へ戻って電力制御回路１３出
力電圧が今求めたＶｓとなるように制御する。The reader / writer IC 12 is provided with the first
Then, the transmission power is controlled in accordance with the flow shown in FIG. 4 using the second table. In the figure, first, the set value of the output voltage Vs of the power control circuit 13 is initialized (step 41). The initial value at this time may be appropriately determined, for example, the Vs value when k = 0.05 in (Equation 4). Next, a control signal is output to the power control circuit 13 so that the output voltage becomes the initialized set value Vs (step 4).
2) Wait for control timing (step 43). At the control timing, the output signal of the voltage detection circuit 11 is fetched to determine the output voltage V of the amplifier 2 (step 44), and then the coupling coefficient k for V / Vs is determined from the first table (step 45). Then, the value of Vs for the obtained coupling coefficient k is obtained from the second table (Step 46), and the process returns to Step 42 to control the output voltage of the power control circuit 13 to be the Vs just obtained.
【００１５】以上のサイクルを繰り返すことで、非接触
ＩＣカードの受電電力は常にほぼ設定値Ｐ0となるよう
に制御されるので、発熱や過電圧による非接触ＩＣカー
ド回路の損傷を確実に防止でき、安定な動作を実現でき
る。なお図４の制御サイクルの周期としては、非接触Ｉ
Ｃカードが人に所持されて移動したときの結合係数の変
化に追従できればよいから、例えば２０ｍsec程度に設
定しておけばよく、ＩＣ１２のＣＰＵへのオーバーヘッ
ドとしてはわずかなものでよく、他の動作の妨害となる
ことはない。By repeating the above cycle, the received power of the non-contact IC card is controlled so as to be almost always at the set value P0, so that damage to the non-contact IC card circuit due to heat generation or overvoltage can be reliably prevented. Stable operation can be realized. The cycle of the control cycle shown in FIG.
It is only necessary to be able to follow the change of the coupling coefficient when the C card is carried by a person and moves. Therefore, it may be set to, for example, about 20 msec, and the overhead of the CPU of the IC 12 may be slight, and other operations may be performed. It does not interfere with
【００１６】図５は、本発明になるリーダ／ライタ装置
の別の構成例を示すブロック図で、図１の構成と異なる
のは、図１の電圧検知回路１１に変わって電流検知回路
１４を設けていることである。この構成例では増幅器２
の出力電流Ｉを電流検知回路１４で検出して電流信号を
出力するが、２つのアンテナの結合度ｋと増幅器２の出
力電流Ｉとの間の関係は、電力制御回路１３出力電圧Ｖ
ｓをパラメータとして求めると図６のようになる。この
関係はやはり図２の等価回路を用いて図３のときと同じ
回路定数を与えてシミュレートした結果である。FIG. 5 is a block diagram showing another configuration example of the reader / writer device according to the present invention. The difference from the configuration of FIG. 1 is that a current detection circuit 14 is provided instead of the voltage detection circuit 11 of FIG. It is provided. In this configuration example, the amplifier 2
Is detected by the current detection circuit 14 to output a current signal. The relationship between the coupling k between the two antennas and the output current I of the amplifier 2 is determined by the output voltage V of the power control circuit 13.
When s is obtained as a parameter, the result is as shown in FIG. This relationship is also a result of simulation using the equivalent circuit of FIG. 2 and giving the same circuit constants as in FIG.
【００１７】図５にみられるように、両アンテナの結合
係数ｋの増大とともに出力電流Ｉは単調に減少してい
て、電力制御回路出力電圧Ｖｓと出力電流Ｉがわかれば
結合係数ｋが一意に定まる。そして出力電流Ｉが電圧Ｖ
ｓに比例するのも図３の場合と同様である。As shown in FIG. 5, the output current I monotonously decreases with the increase of the coupling coefficient k of both antennas. If the output voltage Vs of the power control circuit and the output current I are known, the coupling coefficient k is uniquely determined. Is determined. And the output current I is the voltage V
It is the same as in FIG. 3 that is proportional to s.
【数６】Ｉ＝Ｖｓ・ｈ（ｋ） 従ってこの場合は図１の場合と違ってＩ／Ｖｓとｈ
（ｋ）の関係を前述の第１テーブルに代わるテーブル
（第３テーブルという）として用意しておけば、Ｖｓと
Ｉの検出値から結合係数ｋが求められる。そうすると求
めたｋに対して適切な受電電力Ｐ0を非接触ＩＣカード
に与える電圧Ｖｓが前述の第２テーブル（数４）の関係
から求められので、やはり図１と同様な制御が可能とな
る。このときのＩＣ１２における制御フローを図７に示
す。これはステップ７４で電圧Ｖに変わって電流Ｉを求
め、ステップ７５で参照するテーブルを前述の第３テー
ブルとしたものであって、他の部分は図４と同じであ
る。なお、図４、図７のいずれにおいても、テーブルに
代わって近似関数を用いてもよいことはいうまでもな
い。I = Vs · h (k) Therefore, in this case, unlike the case of FIG. 1, I / Vs and h
If the relationship (k) is prepared as a table (referred to as a third table) instead of the above-described first table, the coupling coefficient k can be obtained from the detected values of Vs and I. Then, the voltage Vs for applying the appropriate received power P0 to the non-contact IC card with respect to the obtained k is obtained from the relationship of the above-described second table (Equation 4), so that the same control as in FIG. 1 can be performed. FIG. 7 shows a control flow in the IC 12 at this time. In this case, the current I is obtained in step 74 instead of the voltage V, and the table referred to in step 75 is the third table described above, and the other parts are the same as those in FIG. It is needless to say that an approximation function may be used in place of the table in both FIG. 4 and FIG.
【００１８】以上のようにして、非接触ＩＣカードでの
過剰な発熱や過電圧による損傷を防止することができる
が、そのための出力電力の制御にあたっては、非接触Ｉ
Ｃカードでの所要電力に多少の余裕を持たせて制御誤差
があっても確実に非接触ＩＣカードの動作を保証するよ
うにする。従ってレギュレータ４に於ける多少の余分な
発熱は避けられず、正規動作による各回路からの発熱も
ある。このため、非接触ＩＣカードを動作範囲内に長時
間放置したときには、電圧検知回路１１または電流検知
回路１４の出力信号をＩＣ１２で監視し、その変化分Δ
ＶまたはΔＩが所定値をこえたときにタイマーを起動
し、その後そのタイマーの設定時間をオーバーして検出
値ＶまたはＩが所定値以上の変化しないときは、非接触
ＩＣカードが動作範囲内に放置されたものと判断して電
力制御回路１３の出力電圧Ｖｓを０かあるいは大幅に低
下させるようにする。上記のタイマーとしてはＩＣ１２
の内臓タイマーあるいはソフトで実現すればよく、また
タイマー設定時間としては通常の非接触ＩＣカードの処
理に要する時間の例えば１０倍程度の値にして於けばよ
い。このような機構を組み込めば、非接触ＩＣカードが
動作範囲に放置されたときでも、不要な電力消費を防止
し、また発熱等による破損をより確実に防止できる。As described above, it is possible to prevent damage due to excessive heat generation and overvoltage in the non-contact IC card.
The power required by the C card is given some margin so that the operation of the non-contact IC card is guaranteed even if there is a control error. Therefore, some extra heat generation in the regulator 4 is inevitable, and there is also heat generation from each circuit due to normal operation. Therefore, when the non-contact IC card is left in the operation range for a long time, the output signal of the voltage detection circuit 11 or the current detection circuit 14 is monitored by the IC 12, and the change Δ
When V or ΔI exceeds a predetermined value, a timer is started, and when the detected value V or I does not change more than a predetermined value after exceeding the set time of the timer, the non-contact IC card is within the operating range. The output voltage Vs of the power control circuit 13 is determined to be zero or significantly reduced by judging that the power control circuit 13 has been left unattended. The above timer is IC12
The timer may be set by a built-in timer or software, and the timer setting time may be set to, for example, about 10 times the time required for normal non-contact IC card processing. By incorporating such a mechanism, even when the non-contact IC card is left in the operating range, unnecessary power consumption can be prevented, and damage due to heat generation or the like can be more reliably prevented.
【００１９】[0019]
【発明の効果】本発明によれば、非接触ＩＣカードが動
作範囲のどこにあっても、また動作範囲の中に長時間放
置されても、発熱や過電圧のために損傷を受けるのを確
実に防止できる。According to the present invention, it is ensured that the contactless IC card will not be damaged due to heat generation or overvoltage even if it is in the operating range or left in the operating range for a long time. Can be prevented.
【図１】本発明になるリーダ／ライタ装置の構成例を示
すブロック図である。FIG. 1 is a block diagram illustrating a configuration example of a reader / writer device according to the present invention.
【図２】非接触ＩＣカードへの電力伝送系統の等価回路
である。FIG. 2 is an equivalent circuit of a power transmission system to a contactless IC card.
【図３】リーダ／ライタ装置のアンテナと非接触ＩＣカ
ードのアンテナの結合係数ｋに対する増幅器出力電圧Ｖ
の関係を示す図である。FIG. 3 shows an amplifier output voltage V with respect to a coupling coefficient k between an antenna of a reader / writer device and an antenna of a non-contact IC card.
FIG.
【図４】図１のＩＣ１２による電力制御のフローであ
る。FIG. 4 is a flowchart of power control by the IC 12 of FIG. 1;
【図５】本発明になるリーダ／ライタ装置の別の構成例
を示すブロック図である。FIG. 5 is a block diagram showing another configuration example of the reader / writer device according to the present invention.
【図６】リーダ／ライタ装置のアンテナと非接触ＩＣカ
ードのアンテナの結合係数ｋに対する増幅器出力電流Ｉ
の関係を示す図である。FIG. 6 shows an amplifier output current I with respect to a coupling coefficient k between an antenna of a reader / writer device and an antenna of a non-contact IC card.
FIG.
【図７】図４のＩＣ１２による電力制御のフローであ
る。FIG. 7 is a flowchart of power control by the IC 12 of FIG. 4;
【図８】従来のリーダ／ライタ装置の構成説明図であ
る。FIG. 8 is a diagram illustrating a configuration of a conventional reader / writer device.
２ 増幅器 １１ 電圧検知回路 １２ リーダ／ライタ用ＩＣ １３ 電力制御回路 １４ 電流検知回路 2 Amplifier 11 Voltage detection circuit 12 Reader / writer IC 13 Power control circuit 14 Current detection circuit
───────────────────────────────────────────────────── フロントページの続き (72)発明者 宮下 信一 東京都中野区東中野三丁目14番20号 国際 電気株式会社内 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shinichi Miyashita 3-14-20 Higashinakano, Nakano-ku, Tokyo Inside Kokusai Electric Corporation
Claims (4)
アンテナの電磁結合によって非接触ＩＣカードへ電力を
供給する機能を有したリーダ／ライタ装置であって、 自装置のアンテナへ供給する高周波供給電力を制御する
ための電力制御手段と、 自装置のアンテナへの入力高周波電圧を検出するための
電圧検出手段と、 該手段により検出された入力高周波電圧と前記電力制御
手段の出力電圧とから非接触ＩＣカードのアンテナと自
装置のアンテナの結合係数を求めるための結合係数算出
手段と、 該手段により求められた結合係数から非接触ＩＣカード
の受電電力が予め定められた値となるように前記電力制
御手段の出力電圧を制御するための制御手段と、 を備えたことを特徴とする非接触ＩＣカード用リーダ／
ライタ装置。1. A reader / writer device having a function of supplying power to a non-contact IC card by electromagnetic coupling between an antenna of the non-contact IC card and an antenna of its own device, wherein a high-frequency supply is supplied to an antenna of its own device. Power control means for controlling power; voltage detection means for detecting an input high-frequency voltage to the antenna of the own device; and a non-linear signal based on the input high-frequency voltage detected by the means and the output voltage of the power control means. A coupling coefficient calculating means for calculating a coupling coefficient between the antenna of the contact IC card and the antenna of the own device; and a coupling coefficient calculating means for determining the received power of the non-contact IC card from the coupling coefficient determined by the means to a predetermined value. Control means for controlling the output voltage of the power control means; and
Writer device.
アンテナの電磁結合によって非接触ＩＣカードへ電力を
供給する機能を有したリーダ／ライタ装置であって、 自装置のアンテナへ供給する高周波供給電力を制御する
ための電力制御手段と、 自装置のアンテナへの入力高周波電流を検出するための
電流検出手段と、 該手段により検出された入力高周波電流と前記電力制御
手段の出力電圧とから非接触ＩＣカードのアンテナと自
装置のアンテナの結合係数を求めるための結合係数算出
手段と、 該手段により求められた結合係数から非接触ＩＣカード
の受電電力が予め定められた値となるように前記電力制
御手段の出力電圧を制御するための制御手段と、 を備えたことを特徴とする非接触ＩＣカード用リーダ／
ライタ装置。2. A reader / writer device having a function of supplying power to a non-contact IC card by electromagnetic coupling between an antenna of the non-contact IC card and an antenna of its own device, wherein a high-frequency supply to the antenna of its own device is provided. Power control means for controlling power; current detection means for detecting a high-frequency current input to an antenna of the own device; and a non-linear signal based on an input high-frequency current detected by the means and an output voltage of the power control means. A coupling coefficient calculating means for calculating a coupling coefficient between the antenna of the contact IC card and the antenna of the own device; and a coupling coefficient calculating means for determining the received power of the non-contact IC card from the coupling coefficient determined by the means to a predetermined value. Control means for controlling the output voltage of the power control means; and
Writer device.
が予め定めた時間以上変化しなかったときはこれを検出
し、前記電力制御手段の出力電圧を低下させる第２の制
御手段を付加したことを特徴とする請求項１に記載の非
接触ＩＣカード用リーダ／ライタ装置。A second control unit for detecting when the high-frequency voltage detected by the voltage detection unit has not changed for a predetermined time or more, and reducing the output voltage of the power control unit; The reader / writer device for a non-contact IC card according to claim 1, wherein:
が予め定めた時間以上変化しなかったときはこれを検出
し、前記電力制御手段の出力電圧を低下させる第２の制
御手段を付加したことを特徴とする請求項２に記載の非
接触ＩＣカード用リーダ／ライタ装置。4. A second control means for detecting when the high-frequency current detected by said current detection means has not changed for a predetermined time or more, and lowering the output voltage of said power control means, has been added. The non-contact IC card reader / writer device according to claim 2, wherein
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13983398A JP3884565B2 (en) | 1998-05-21 | 1998-05-21 | Non-contact IC card reader / writer device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13983398A JP3884565B2 (en) | 1998-05-21 | 1998-05-21 | Non-contact IC card reader / writer device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH11338983A true JPH11338983A (en) | 1999-12-10 |
| JP3884565B2 JP3884565B2 (en) | 2007-02-21 |
Family
ID=15254566
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP13983398A Expired - Fee Related JP3884565B2 (en) | 1998-05-21 | 1998-05-21 | Non-contact IC card reader / writer device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3884565B2 (en) |
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| WO2013145488A1 (en) * | 2012-03-30 | 2013-10-03 | 株式会社エクォス・リサーチ | Power transmission system |
| JP2013211932A (en) * | 2012-03-30 | 2013-10-10 | Equos Research Co Ltd | Power transmission system |
| CN104170209A (en) * | 2012-03-30 | 2014-11-26 | 株式会社爱考斯研究 | Power transmission system |
| US9467204B2 (en) | 2013-10-31 | 2016-10-11 | Samsung Electronics Co., Ltd. | Voltage regulator with current mirroring circuitry for transmitters for near field communication (NFC) devices and chips, and electronic devices including such NFC chips |
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