JPH05102907A - Eliminating circuit for msk signal component of receiver output - Google Patents
Eliminating circuit for msk signal component of receiver outputInfo
- Publication number
- JPH05102907A JPH05102907A JP25687091A JP25687091A JPH05102907A JP H05102907 A JPH05102907 A JP H05102907A JP 25687091 A JP25687091 A JP 25687091A JP 25687091 A JP25687091 A JP 25687091A JP H05102907 A JPH05102907 A JP H05102907A
- Authority
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- Japan
- Prior art keywords
- output
- signal
- msk
- msk signal
- receiver
- 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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- Circuits Of Receivers In General (AREA)
- Mobile Radio Communication Systems (AREA)
- Noise Elimination (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は車両位置等自動表示シス
テムAutomatic Vehicle Monitoring System等の無線信
号をFM変調した通話用の音声信号に, データ伝送用のFS
変調の例えばMSK変調したデータを重畳して伝送する移
動無線システムに係り、特に受信機の出力(FM復調出力)
の通話用の音声信号に含まれる不要なデータ伝送用の M
SK信号分を除去する回路に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a voice signal for communication in which a radio signal of an automatic vehicle position display system, such as Automatic Vehicle Monitoring System, is FM-modulated, and an FS for data transmission.
Related to mobile radio systems that superimpose and transmit, for example, MSK-modulated data for modulation, especially receiver output (FM demodulation output)
M for unnecessary data transmission included in the voice signal for
The present invention relates to a circuit for removing the SK signal component.
【０００２】[0002]
【従来の技術】従来の受信機出力の MSK信号分の除去回
路は、図３に示す如く、受信機RXのFM復調出力の通話用
の音声出力とデータ伝送用の MSK信号出力とをオン/ オ
フするアナログスイッチ(SW1) 10を、該受信機の出力の
データ用モデムMODEMのデモジュレータDEMにて前記受信
機RxのFM復調出力の中のデータ伝送用の MSK信号を検出
した時の MSK検出出力L によりオフとして MSK信号分を
除去し、該 MSK信号を検出しない時の MSK検出出力H に
より、アナログスイッチ(SW1) 10をオンして、通話用の
音声信号を出力していた。2. Description of the Related Art As shown in FIG. 3, a conventional receiver output MSK signal removal circuit turns on / off a voice output for communication of a FM demodulation output of a receiver RX and an MSK signal output for data transmission. Turn off the analog switch (SW 1 ) 10 to the MSK when the data transmission MSK signal in the FM demodulation output of the receiver Rx is detected by the demodulator DEM of the data modem MODEM for the output of the receiver. The detection output L is turned off to remove the MSK signal component, and the MSK detection output H when the MSK signal is not detected turns on the analog switch (SW 1 ) 10 to output a voice signal for communication.
【０００３】[0003]
【発明が解決しようとする課題】この従来の方法では、
受信電界の変動状況（受信信号の一時断）および受信
機RxのFM復調部(IC)とデータ用モデムの MSK信号検出の
遅延時間とにより，受信機RxのFM復調出力のMSK 信号の
先頭部分がアナログスイッチ(SW1)10 にて除去されず音
声出力に混じるので、音声信号が聞き取り難い。音声
信号波と MSK信号波とが複数の移動局から送出され或る
１つの受信機Rxで重複受信した時で其の MSK信号波がや
や強い場合、受信機Rxが該重複した信号をFM復調しデー
タ用モデムMODEM のデモジュレータDEM が受信機RxのFM
復調出力からデータの MSK信号を検出した時の検出出力
L によりアナログスイッチ(SW1)10をオフして音声出力
の送出を遮断するため、音声出力が途切れて聞き取り難
くなるという問題があった。本発明の目的は、受信電界
が変動し受信信号が一時断となったり受信機のFM復調部
(IC)とデータ用モデムの MSK信号検出に遅延時間が有っ
ても,MSK信号分の除去用スイッチ10にて, 受信機のFM復
調出力の音声出力に MSK信号分が混じることが無く、又
音声信号波と MSK信号波とが複数の移動局から送出され
其の MSK信号波がやや強い場合でも受信機のFM復調出力
の音声出力が MSK信号分の除去用スイッチ10にて, 途切
れて聞き取り難くなるということの無いような受信機出
力のMSK信号分の除去（消去) 回路を実現することにあ
る。SUMMARY OF THE INVENTION In this conventional method,
The leading part of the MSK signal of the FM demodulation output of the receiver Rx depends on the fluctuation status of the reception electric field (temporary interruption of the reception signal) and the delay time of the MSK signal detection of the FM demodulation unit (IC) of the receiver Rx and the data modem. Is not removed by the analog switch (SW 1 ) 10 and is mixed in the audio output, making it difficult to hear the audio signal. When the voice signal wave and the MSK signal wave are transmitted from multiple mobile stations and received by one receiver Rx in duplicate, and the MSK signal wave is slightly strong, the receiver Rx performs FM demodulation of the duplicated signal. The demodulator DEM of the data modem MODEM is the FM of the receiver Rx.
Detection output when data MSK signal is detected from demodulation output
Since the analog switch (SW 1 ) 10 is turned off by L to interrupt the output of the audio output, there is a problem that the audio output is interrupted and becomes difficult to hear. The object of the present invention is to change the received electric field and temporarily interrupt the received signal, or to use the FM demodulator of the receiver.
Even if there is a delay time in detecting the MSK signal between the (IC) and the data modem, the switch 10 for removing the MSK signal does not mix the MSK signal with the audio output of the FM demodulation output of the receiver. Also, even if the voice signal wave and the MSK signal wave are transmitted from multiple mobile stations and the MSK signal wave is slightly strong, the voice output of the FM demodulation output of the receiver is interrupted by the MSK signal removal switch 10. It is to realize a removal (elimination) circuit for the MSK signal of the receiver output that does not make it difficult to hear.
【０００４】[0004]
【課題を解決するための手段】この目的を達成するため
の本発明の基本構成を図１の原理図に示す。１は受信機
RXのFM復調出力を、受信電界が変動し受信信号が一時断
となる時間やFM復調部(IC)とデータ用モデムの MSK信号
検出の遅延時間に相当する一定時間だけ遅延させる遅延
回路である。２は遅延回路1 の出力である受信機RXのFM
復調出力の音声信号と MSK信号との混在出力からMSK信
号分を除去するフィルタである。3 はデータ用モデムMO
DEMが MSK信号を検出しない時の MSK検出出力L の反転
出力Hによりオンして前記フィルタ2 の出力を通過させ
る第２のアナログスイッチSW2である。そして、第２の
アナログスイッチSW2 3 は、データ用モデムMODEMが受
信機RxのFM復調出力から MSK信号を検出しない時の検出
出力L の反転出力H によりオンし, 第１のアナログスイ
ッチSW1 10は、該 MSK信号を検出しない時の検出出力L
によりオフするように構成する。The basic configuration of the present invention for achieving this object is shown in the principle diagram of FIG. 1 is the receiver
This is a delay circuit that delays the FM demodulation output of RX by a fixed time corresponding to the time when the received signal fluctuates due to fluctuations in the received electric field and the delay time for detecting the MSK signal of the FM demodulator (IC) and data modem. .. 2 is the FM of the receiver RX which is the output of the delay circuit 1.
This filter removes the MSK signal component from the mixed output of the demodulated audio signal and the MSK signal. 3 is a data modem MO
The second analog switch SW 2 is turned on by the inverted output H of the MSK detection output L when the DEM does not detect the MSK signal and passes the output of the filter 2. The second analog switch SW 2 3 is turned on by the inverted output H of the detection output L when data modem MODEM does not detect the MSK signal from the FM demodulated output of the receiver Rx, the first analog switch SW 1 10 is the detection output L when the MSK signal is not detected
It is configured to turn off by.
【０００５】[0005]
【作用】本発明では、その遅延回路1 が、受信機RXのFM
復調出力を, 受信電界が変動し受信信号が一時断となっ
た時間やFM復調部(IC)とデータ用モデムの MSK信号検出
の遅延時間に相当する一定時間だけ遅延させて、データ
用モデムMODEM のデモジュレータDEMが該受信機RXの出
力のFM復調出力から直ぐ MSK信号を検出して出力した M
SK検出出力L/Hよりも遅く出力する様にする。そしてフ
ィルタ2 が、遅延回路1 の出力の受信機RXのFM復調出力
の音声信号と MSK信号との混在出力から MSK信号分を除
去して、第２のアナログスイッチ(SW2) 3 へ送出する。
そして第２のアナログスイッチ(SW2) 3 が、データ用モ
デムMODEMの出力の MSK検出出力Lの反転出力Hによりオ
ンして前記フィルタ2 の出力である音声出力のみを通し
て出力する。この MSK検出出力L の時、第１のアナログ
スイッチ(SW1) 10はオフとなり、受信機のFM復調出力の
音声信号と MSK信号の混合出力の通過は遮断されて出力
されない。従って本発明の受信機出力の MSK信号分の除
去回路によれば、受信電界が変動して受信信号が一時断
となったり受信機のFM復調部(IC)とデータ用モデムの M
SK信号検出に遅延時間が有っても、遅延回路1,フィルタ
2,第２のアナログスイッチ(SW2) 3 とにより、受信機の
FM復調出力の音声出力が MSK信号分と混じることが無く
出力されるし、又音声信号波と MSK信号波とが複数の移
動局から送出され、其の MSK信号波がやや強い場合でも
受信機のFM復調出力の音声出力から MSK信号分を除去す
る第１のアナログスイッチSW1 10のオフと第２のアナロ
グスイッチSW2 3 のオンとにより、音声出力が途切れて
聞き取り難くなるということが無くなり、従来の問題は
解決される。In the present invention, the delay circuit 1 is the FM of the receiver RX.
The demodulation output is delayed by a fixed time corresponding to the time when the reception signal fluctuates due to fluctuations in the reception electric field and the delay time for detecting the MSK signal between the FM demodulation unit (IC) and the data modem, and the data modem MODEM The demodulator DEM detects the MSK signal immediately from the FM demodulation output of the receiver RX and outputs it.
The SK detection output is set to output later than L / H. Then, the filter 2 removes the MSK signal component from the mixed output of the audio signal and the MSK signal of the FM demodulated output of the receiver RX of the output of the delay circuit 1 and sends it to the second analog switch (SW 2 ) 3. ..
The second analog switch (SW 2 ) 3 is turned on by the inverted output H of the MSK detection output L of the output of the data modem MODEM, and outputs only through the audio output which is the output of the filter 2. At the time of this MSK detection output L, the first analog switch (SW 1 ) 10 is turned off, and the passage of the mixed output of the audio signal of the FM demodulation output of the receiver and the MSK signal is blocked and is not output. Therefore, according to the removal circuit for the MSK signal of the receiver output of the present invention, the received signal fluctuates and the received signal is temporarily interrupted, or the FM demodulator (IC) of the receiver and the M
Even if there is a delay time in SK signal detection, delay circuit 1, filter
By the 2nd and 2nd analog switch (SW 2 ) 3,
The audio output of the FM demodulation output is output without being mixed with the MSK signal, and the audio signal wave and the MSK signal wave are sent from multiple mobile stations, and even if the MSK signal wave is slightly strong, the receiver The first analog switch SW 1 10 and the second analog switch SW 2 3 that remove the MSK signal component from the FM demodulation output voice output are not interrupted, making it difficult to hear. , The conventional problem is solved.
【０００６】[0006]
【実施例】図２は本発明の実施例の受信機出力の MSK信
号分の除去回路のブロック図である。先ず(1) 通常の通
話用の音声信号のみを受信する場合は、受信機RxのFM復
調出力である音声信号を、第１のアナログスイッチSW1
10がデータ用モデムMODEMの MSK検出出力L/H の MSK信
号を検出しない時の検出出力H によりオンして、FM復調
出力の音声信号を通過させ、AMPで増幅しスピーカから
出力する。この音声信号のみで MSK信号を検出しない M
SK検出出力H の時は、其の反転出力L により第２のアナ
ログスイッチSW2 3 はオフの状態となり、受信機出力の
音声信号は第１のアナログスイッチSW1 10を通って出力
される。次に (2)データ伝送用の MSK信号(1500±300H
z)を受信する場合と其の MSK信号と通話用の音声信号と
を重複して受信する場合は、受信機Rxの FM 復調出力で
ある音声信号と MSK信号の混在した出力を、第１のアナ
ログスイッチSW1 10は、データ用モデムMODEM の MSK検
出出力H/L の中のMSK 信号を検出した時の MSK検出出力
L によりオフし、その混在出力の AMPへの送出を遮断す
る。その代り、第２のアナログスイッチSW2 ３は、デー
タ用モデムMODEM がMSK信号を検出した時の検出出力L
の反転出力H によりオンし、該混在出力のフィルタ2 の
低域通過フィルタLPF ( カットオフ周波数が 900Hz)を
通過した音声出力のみを通し、AMPで増幅しスピーカか
ら出力する。この MSK信号を検出した MSK検出出力L の
時は、第１のアナログスイッチSW1 10はオフ状態とな
り、受信機出力の音声信号は、遅延回路1,フィルタ2 を
通り,第２のアナログスイッチSW2 ３を通ってAMP,スピ
ーカへ送出される。そしてデータ用モデムMODEM が受信
機RxのFM復調出力のMSK信号を検出して出力する MSK検
出出力L/Hが、該FM復調出力が電界の状態により通常時
より遅れて 10msec 〜50msecだけ遅れて出力されるとす
ると、その場合は該FM復調出力を例えば 60msec〜100ms
ec だけ遅延させる遅延回路1を設けることにより、その
MSK検出出力L/Hが、FM復調出力の音声とMSK 信号の混
在出力より早く出力される。そのため、第１のアナログ
スイッチSW1 10のオン/ オフの切替動作が其の入力の M
SK信号の先頭部分を誤って誤出力することは無い。な
お、本発明では通話用の音声信号に重畳されるデータ伝
送用の信号としてFS変調の一種の MSK信号について述べ
たが、この MSK信号に限られず一般のFS信号であれば良
いことは言うまでもない。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 2 is a block diagram of a removing circuit for an MSK signal of a receiver output according to an embodiment of the present invention. First, (1) When receiving only the voice signal for normal communication, the voice signal which is the FM demodulation output of the receiver Rx is set to the first analog switch SW 1
10 turns on by the detection output H when the MSK detection output L / H of the data modem MODEM does not detect the MSK signal, passes the audio signal of the FM demodulation output, amplifies it with AMP, and outputs it from the speaker. This audio signal alone does not detect the MSK signal M
When SK detection output H, the second analog switch SW 2 3 by its inverted output L becomes off, the audio signal of the receiver output is outputted through the first analog switch SW 1 10. Next, (2) MSK signal for data transmission (1500 ± 300H
z) and the case where the MSK signal and the voice signal for communication are received in duplicate, the mixed output of the voice signal and the MSK signal, which is the FM demodulation output of the receiver Rx, is output as the first Analog switch SW 1 10 is the MSK detection output when the MSK signal in the MSK detection output H / L of the data modem MODEM is detected.
It turns off by L and cuts off the sending of the mixed output to AMP. Instead, the second analog switch SW 2 3, the detection output L when data modem MODEM detects an MSK signal
It is turned on by the inverted output H of, and only the audio output that has passed through the low pass filter LPF (cutoff frequency is 900 Hz) of the mixed output filter 2 is passed, amplified by AMP, and output from the speaker. When the MSK signal the detected MSK detection output L is first analog switch SW 1 10 is turned off, the audio signal of the receiver output, the delay circuit 1, through the filter 2, a second analog switch SW AMP through 2 3, is sent to the speaker. Then, the data modem MODEM detects and outputs the MSK signal of the FM demodulation output of the receiver Rx, and the MSK detection output L / H is delayed by 10 msec to 50 msec after the FM demodulation output is delayed from the normal state due to the electric field state. If it is output, in that case, the FM demodulation output is, for example, 60 msec to 100 ms.
By providing the delay circuit 1 that delays by ec,
The MSK detection output L / H is output earlier than the mixed output of the FM demodulation output voice and MSK signal. Therefore, the switching operation of the first analog switch SW 1 10 on / off of its input M
There is no mistaken output of the beginning part of the SK signal. In the present invention, a kind of MSK signal of FS modulation has been described as a signal for data transmission to be superimposed on a voice signal for communication, but needless to say, a general FS signal is not limited to this MSK signal. ..
【０００７】[0007]
【発明の効果】以上説明した如く、本発明によれば、受
信機出力が MSK信号のみの時の其の先頭部の除去および
MSK信号と音声信号が重複して受信された時, 特に通話
中に他の移動局からの MSK信号の割込みが有った時の音
声出力の途切れを防止できるので、無線信号で伝送デー
タを通話用音声に重畳して伝送する移動無線システムの
音声信号による通話がスムーズに行われるという大きな
効果が得られる。As described above, according to the present invention, when the receiver output is only the MSK signal, the removal of the leading part and
When the MSK signal and the voice signal are received in duplicate, the interruption of the voice output can be prevented, especially when there is an interruption of the MSK signal from another mobile station during a call, so the transmission data can be called by the wireless signal. A great effect is obtained that a call is smoothly carried out by a voice signal of a mobile radio system that is transmitted by being superposed on a voice for use.
【図１】 本発明の受信機出力の MSK信号分の除去回路
の基本構成を示す原理図FIG. 1 is a principle diagram showing a basic configuration of a removal circuit for a MSK signal component of a receiver output according to the present invention.
【図２】 本発明の実施例の受信機出力の MSK信号分の
除去回路のブロック図FIG. 2 is a block diagram of a removal circuit for an MSK signal of a receiver output according to the embodiment of the present invention.
【図３】 従来の受信機出力の MSK信号分の除去回路の
ブロック図[Fig. 3] Block diagram of a conventional receiver output MSK signal removal circuit
１は遅延回路、２はフィルタ、３は第２のアナログスイ
ッチSW2 、10は第１のアナログスイッチSW1 である。Reference numeral 1 is a delay circuit, 2 is a filter, 3 is a second analog switch SW 2 , and 10 is a first analog switch SW 1 .
Claims (1)
出力とデータ伝送用のMSK信号出力の混在した出力から
該MSK信号分のみを該受信機のFM復調出力からMSK信号を
検出した時のデータ用モデム(DEM)の出力の MSK検出出
力(L) により動作する第１のアナログスイッチ(10)のオ
フ状態により除去して音声出力のみを出力する MSK信号
分の除去回路において、該受信機(Rx)のFM復調出力を,
受信電界の変動により受信信号が一時断となる時間やFM
復調とデータ用モデムの MSK信号検出の遅延時間に相当
する一定時間だけ遅延させる遅延回路(1) と、該遅延回
路の出力の音声出力と MSK信号出力の混在出力から MSK
信号分を除去するフィルタ(2) と、前記データ用モデム
(DEM)の出力の MSK検出出力(L)の反転出力(H) によりオ
ンして前記フィルタ( 2)の出力を通過させる第２のアナ
ログスイッチ(3) とを具え、該データ用モデム(DEM)が
MSK信号を検出しない時の検出出力(H)によりオンし其れ
までFM復調出力の必要な音声信号と不要な MSK信号分の
混在出力を通過させていた第１のアナログスイッチ(10)
をオフとして該混在出力の送出を遮断し、前記MSK信号
を検出した時の MSK検出出力(L) の反転出力(H) により
第２のアナログスイッチ(3) をオンすることにより前記
フィルタ(2) の出力の音声信号のみを送出することを特
徴とした受信機出力の MSK信号分の除去回路。1. An MSK signal is output from an FM demodulated output of the receiver from a mixed output of a voice output for communication of a FM demodulated output of a receiver (Rx) and an MSK signal output for data transmission. In the removal circuit for the MSK signal that removes by the off state of the first analog switch (10) that operates by the MSK detection output (L) of the output of the data modem (DEM) when it is detected and outputs only the audio output , FM demodulation output of the receiver (Rx),
Time or FM when the received signal is temporarily interrupted due to fluctuations in the received electric field
A delay circuit (1) that delays for a fixed time equivalent to the delay time for demodulation and data modem MSK signal detection, and a mixed output of voice output and MSK signal output of the delay circuit
A filter (2) for removing the signal component and the data modem
A second analog switch (3) that is turned on by the inverted output (H) of the MSK detection output (L) of the output of (DEM) and allows the output of the filter (2) to pass, and the data modem (DEM) )But
The first analog switch (10) that was turned on by the detection output (H) when the MSK signal was not detected, and was passing the mixed output of the voice signal required for FM demodulation output and the unnecessary MSK signal until then.
Is turned off to interrupt the transmission of the mixed output, and by turning on the second analog switch (3) by the inverted output (H) of the MSK detection output (L) when the MSK signal is detected, the filter (2 ) The output circuit for the MSK signal of the receiver output, which sends out only the audio signal output.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3256870A JP2722892B2 (en) | 1991-10-04 | 1991-10-04 | Removal circuit for MSK signal of receiver output |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3256870A JP2722892B2 (en) | 1991-10-04 | 1991-10-04 | Removal circuit for MSK signal of receiver output |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05102907A true JPH05102907A (en) | 1993-04-23 |
| JP2722892B2 JP2722892B2 (en) | 1998-03-09 |
Family
ID=17298567
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3256870A Expired - Lifetime JP2722892B2 (en) | 1991-10-04 | 1991-10-04 | Removal circuit for MSK signal of receiver output |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2722892B2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005253044A (en) * | 2003-11-27 | 2005-09-15 | Kobe Steel Ltd | Wireless communications apparatus |
| JP2005531202A (en) * | 2002-06-21 | 2005-10-13 | ワイデファイ インコーポレイテッド | Wireless local area network repeater |
| JP2006503481A (en) * | 2002-10-15 | 2006-01-26 | ワイデファイ インコーポレイテッド | Wireless local area network repeater with automatic gain control to extend network coverage |
| US8885688B2 (en) | 2002-10-01 | 2014-11-11 | Qualcomm Incorporated | Control message management in physical layer repeater |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63151283A (en) * | 1986-12-16 | 1988-06-23 | Sony Corp | Transceiver |
| JPS63160442A (en) * | 1986-12-24 | 1988-07-04 | Hitachi Denshi Ltd | Data transmission system |
-
1991
- 1991-10-04 JP JP3256870A patent/JP2722892B2/en not_active Expired - Lifetime
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63151283A (en) * | 1986-12-16 | 1988-06-23 | Sony Corp | Transceiver |
| JPS63160442A (en) * | 1986-12-24 | 1988-07-04 | Hitachi Denshi Ltd | Data transmission system |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005531202A (en) * | 2002-06-21 | 2005-10-13 | ワイデファイ インコーポレイテッド | Wireless local area network repeater |
| US8885688B2 (en) | 2002-10-01 | 2014-11-11 | Qualcomm Incorporated | Control message management in physical layer repeater |
| JP2006503481A (en) * | 2002-10-15 | 2006-01-26 | ワイデファイ インコーポレイテッド | Wireless local area network repeater with automatic gain control to extend network coverage |
| JP2005253044A (en) * | 2003-11-27 | 2005-09-15 | Kobe Steel Ltd | Wireless communications apparatus |
| JP4544976B2 (en) * | 2003-11-27 | 2010-09-15 | 株式会社神戸製鋼所 | Wireless communication device |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2722892B2 (en) | 1998-03-09 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 19971028 |