JPS6281829A - Two-way optical signal transmitter - Google Patents

Two-way optical signal transmitter

Info

Publication number
JPS6281829A
JPS6281829A JP60221177A JP22117785A JPS6281829A JP S6281829 A JPS6281829 A JP S6281829A JP 60221177 A JP60221177 A JP 60221177A JP 22117785 A JP22117785 A JP 22117785A JP S6281829 A JPS6281829 A JP S6281829A
Authority
JP
Japan
Prior art keywords
circuit
signal
transmission
reception
light emitting
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.)
Pending
Application number
JP60221177A
Other languages
Japanese (ja)
Inventor
Hideo Shimizu
秀雄 清水
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Fuji Electric Co Ltd
Original Assignee
Fuji Electric Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Fuji Electric Co Ltd filed Critical Fuji Electric Co Ltd
Priority to JP60221177A priority Critical patent/JPS6281829A/en
Publication of JPS6281829A publication Critical patent/JPS6281829A/en
Pending legal-status Critical Current

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  • Optical Communication System (AREA)

Abstract

PURPOSE:To eliminate the effect of a reflected light in binary-coding a reception signal by providing an automatic gain control circuit synchronously with a transmission signal to an amplifier circuit of a reception section. CONSTITUTION:A transmission signal P inputted from an input terminal 1b equipments a light emitting element 1a via a drive circuit 1c at transmission and the transmitted light is sent via a T-coupler 3. On the other hand, the received light from a fiber C reaches a photodetecting element 2a via the T- coupler 3 at the reception, is subjected to photoelectric conversion and a binarization reception signal Q is outputted from an output terminal 2b via an amplifier circuit 2c and a binarization circuit 2d at the reception. In this case, since the automatic gain control circuit 5 uses a transmission signal P to change the amplification factor of the amplifier circuit 2c, the reflection signal after amplification is suppressed within the dynamic range of the binary coding circuit to eliminate the effect of the reflected light.

Description

【発明の詳細な説明】 〔発明の属する技術分野〕 この発明は光通信に用いられる単線光ファイバによる双
方向データ伝送用光信号伝送装置に関する。
DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to an optical signal transmission device for bidirectional data transmission using a single optical fiber used in optical communications.

〔従来技術とその問題点〕[Prior art and its problems]

この種の双方向光信号伝送装置としては第5図のプロ、
り図に示す構成のものが知られている。
As this type of bidirectional optical signal transmission device, the professional shown in Fig. 5 is used.
The configuration shown in the figure is known.

発光部lは発光素子1a、入力端子1bおよび駆動回路
1cよりなり、受光部2は受光素子2a。
The light emitting section 1 includes a light emitting element 1a, an input terminal 1b, and a drive circuit 1c, and the light receiving section 2 includes a light receiving element 2a.

出力端子2b、増幅回路2Cおよび2値化回路2dより
なる。ハーフミラ−で構成されたT−カプラ3と発光素
子1aは第1の光ファイバAで結合され、受光素子2a
は第2の光ファイバCで結合されている。Cは伝送用光
ファイバである。送信時は入力端子1bより入力された
送信信号Pが駆動回路ICを介して発光素子1aを駆動
し、発光素子1aより出射された送信光は第lの元ファ
イバへにより導かれT−カプラ3を経由して伝送用光フ
ァイバCに伝送される。受信時は伝送用光ファイバCか
らの受信元をT−カプラ3を介して第2の光ファイバB
に導かれ受光部2に到る。受光部2の受光素子2aで光
電変換され、増幅回路2c。
It consists of an output terminal 2b, an amplifier circuit 2C, and a binarization circuit 2d. The T-coupler 3 composed of a half mirror and the light emitting element 1a are coupled by a first optical fiber A, and the light receiving element 2a
are coupled by a second optical fiber C. C is a transmission optical fiber. At the time of transmission, the transmission signal P input from the input terminal 1b drives the light emitting element 1a via the drive circuit IC, and the transmitted light emitted from the light emitting element 1a is guided to the l-th original fiber and sent to the T-coupler 3. The signal is transmitted to the transmission optical fiber C via. At the time of reception, the reception source from the transmission optical fiber C is connected to the second optical fiber B via the T-coupler 3.
and reaches the light receiving section 2. Photoelectric conversion is performed by the light receiving element 2a of the light receiving section 2, and the amplifier circuit 2c.

2値化回路2dを経て2値化受信信号Qを出力端子2b
より出力する。このような双方向光信号伝導装置は、伝
送ファイバCの長短などによる伝送損失の変動を吸収す
るために2値化回路2dに自動しきい値制御回路を含ま
せたものがあり、この許容変動分はダイナミックレンジ
と呼ばれる。
The binarized received signal Q is output through the binarization circuit 2d to the output terminal 2b.
Output from Some bidirectional optical signal transmission devices include an automatic threshold control circuit in the binarization circuit 2d to absorb variations in transmission loss due to the length of the transmission fiber C, etc. This is called the dynamic range.

第611.第7図はそれぞれこの目動しきい値制御回路
4の構成3よび動作を示すもので、制御回路4は比較器
4aと抵抗体4bとコンデンサ4cとで構成され、比較
器4aの基血電圧■Tは入力電圧V1に応じて質化し2
値化を行っている。単嶽光ファイバ(こよる双方向デー
タ伝送の場合は、T−カプラ3を用いるため発光素子1
aからの送信光はT−カプラ3と伝送用光ファイバCと
の接続部分で端面反射番こよって受光素子2aに入射す
る。
No. 611. FIG. 7 shows the configuration 3 and operation of this eye movement threshold control circuit 4. The control circuit 4 is composed of a comparator 4a, a resistor 4b, and a capacitor 4c, and the base blood voltage of the comparator 4a is shown in FIG. ■T is qualitatively determined according to the input voltage V1.
We are converting into value. Single optical fiber (for bidirectional data transmission, T-coupler 3 is used, so light emitting element 1
The transmitted light from the T-coupler 3 and the transmission optical fiber C enters the light receiving element 2a through end face reflection.

この反射光は光量レベルが受信部2のダイナミックレン
ジを超えると、第8図に示すように送信光と受信光が時
間的iこ接近した場合コンデンサ4cの充放電時間の影
響で基準電圧Vτが追随できず2値化出力Voのパルス
幅歪VL11が増大するという問題があった。
When the light intensity level of this reflected light exceeds the dynamic range of the receiver 2, as shown in FIG. There is a problem in that the pulse width distortion VL11 of the binarized output Vo increases because the pulse width distortion VL11 cannot be followed.

この問題を解決下るには送偏、受信の時…j間隔を増や
してコンデンサの充放電時間を確保すれば良いが、時間
間隔を増やすとその間は伝送路が使用されずデータの伝
送効率が悪くなるという弱点がでてくる。別の解決対策
としてダイナミックレンジを拡大して、反射光の光量レ
ベルをダイナミ、クレンジ内に含める方法があるが、こ
の場合は受信に必要なダイナミックレンジ以上にダイナ
ミ、クレンジを拡大するために回路構成が複雑化し不必
要なコストアップにつながるという問題がある。
To solve this problem, increase the interval between transmission and reception to ensure the charging and discharging time of the capacitor, but if you increase the time interval, the transmission line will not be used during that time, resulting in poor data transmission efficiency. A weakness emerges. Another solution is to expand the dynamic range and include the light intensity level of the reflected light within the dynamic range, but in this case, the circuit is configured to expand the dynamic range beyond the dynamic range required for reception. The problem is that it becomes complicated and leads to unnecessary cost increases.

〔発明の目的〕[Purpose of the invention]

この発明は上述した事情に鑑みなされたもので受信信号
を二値化する際に反射光の′#響を除去することのでき
る双方向元信号伝送装置を提供することを目的とする。
The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a bidirectional original signal transmission device that can eliminate the echo of reflected light when binarizing a received signal.

〔発明の要点〕[Key points of the invention]

この発明では上記目的達成のため、受信部の増幅回路に
送イΔ侶号と同期した自動利得?[Ilj御回路を設け
、これにより高レベルの反射光がある場合には増幅回路
の増幅度を下げ2値化回路でのパルス幅歪に影響が出な
いようにした。
In order to achieve the above-mentioned purpose, this invention provides an automatic gain synchronization with the signal sent to the amplifier circuit of the receiving section. [An Ilj control circuit is provided, whereby when there is a high level of reflected light, the amplification degree of the amplifier circuit is lowered so that the pulse width distortion in the binarization circuit is not affected.

〔発明の実施例〕[Embodiments of the invention]

第1図はこの発明の実施例を示すもので、従来回路(第
5図)における同一構成の部分には同一の符号を符し、
説明を省略する。この発明により従来回路と異なる点は
、受光部2の増幅回路2cと発光部lの入力端子との間
に自動利得制御回路5を設けたことである。この自動利
得制御回路5は、送信信号Pによって増幅回路2cの増
幅度を変化させるものである。
FIG. 1 shows an embodiment of the present invention, and parts having the same configuration as in the conventional circuit (FIG. 5) are denoted by the same reference numerals.
The explanation will be omitted. The present invention differs from conventional circuits in that an automatic gain control circuit 5 is provided between the amplifier circuit 2c of the light receiving section 2 and the input terminal of the light emitting section l. This automatic gain control circuit 5 changes the amplification degree of the amplifier circuit 2c according to the transmission signal P.

第2図と第3図は目動利得制御回路と増幅回路の具体例
で6は電界効果トランジスタ、7は増幅器Roは入力抵
抗体、RF l * l(F 2は固定抵抗体である。
2 and 3 show specific examples of a variable gain control circuit and an amplifier circuit, where 6 is a field effect transistor, 7 is an amplifier Ro is an input resistor, and RF l * l (F 2 is a fixed resistor).

第2図では送信信号PIこより電界効果トランジスタ6
をオン、オフして増幅器7の増幅度を変化させる。増幅
度は送信信号が@l”のとき固定抵抗体1tP2で決ま
り、送・1呂信号”Omのときは固なる。第3図の場合
は送イぎ信号Pにより増幅器7の出力をオン、オフさせ
る。送信1g号が”l”のときには出力がオフとなり、
反射光による受%i信号は出力されない。
In Fig. 2, the field effect transistor 6 is connected to the transmission signal PI.
is turned on and off to change the amplification degree of the amplifier 7. The degree of amplification is determined by the fixed resistor 1tP2 when the transmission signal is @l'', and is fixed when the transmission signal is ``Om''. In the case of FIG. 3, the output of the amplifier 7 is turned on and off by the sending signal P. When the transmitter 1g signal is "l", the output is turned off,
The received %i signal due to reflected light is not output.

第4図はこの発明の実施例の各部の成形を示すチャー1
・で、(alは伝送装置の送(g波形図、(blは図示
しない伝送装置の送信波形図、(clは前記伝送装置の
受光波形図、(dlは前記伝送装置の増幅度の変化を示
す図、(clは前記伝送装置の2値化回路の入力波形図
、(f)は前記伝送装置の2値化回路の出力波形図であ
る。すなわち送信時には送信信号に応じて増幅回路の増
幅度を変化させ、増幅後の反射光信号を2値化回路のダ
イナミックレンジ内に抑えることにより、送信信号と受
信信号との時間間隔が短かくてもパルス幅歪は増大しな
い。
FIG. 4 is chart 1 showing the molding of each part of the embodiment of this invention.
・In, (al is the transmission (g waveform diagram) of the transmission device, (bl is the transmission waveform diagram of the transmission device (not shown), (cl is the reception waveform diagram of the transmission device, and (dl is the change in amplification of the transmission device) (cl is an input waveform diagram of the binarization circuit of the transmission device, and (f) is an output waveform diagram of the binarization circuit of the transmission device. In other words, at the time of transmission, the amplification of the amplifier circuit is performed according to the transmission signal. By changing the frequency and suppressing the amplified reflected light signal within the dynamic range of the binarization circuit, pulse width distortion does not increase even if the time interval between the transmitted signal and the received signal is short.

〔発ψ」の効果〕[Effect of ejection ψ]

この発明によれは、送信信号と同期した自動利得!1J
411回路を増幅回路に付設したことにより、高レベル
の反射光があっても増幅後の信号を2値化回路のダイナ
ミックレンジ内に収めることかでき、安定した受信特性
が得られるので送・受信の時間間隔を拡げる必要がなく
、伝送路の利用効率を高めることができる。
This invention provides automatic gain synchronized with the transmitted signal! 1J
By attaching the 411 circuit to the amplifier circuit, even if there is a high level of reflected light, the amplified signal can be kept within the dynamic range of the binarization circuit, and stable reception characteristics can be obtained, making it easy to transmit and receive. There is no need to widen the time interval, and the efficiency of using the transmission path can be increased.

【図面の簡単な説明】[Brief explanation of drawings]

@1図はこの発明の実施例を示すプロ、り図、第2図、
第二3図は増幅回路と自動利得制御回路の具体例を示す
回路図、第4図はこの発明の実施例における谷部の波形
を示すチャート、第5図は従来の伝送装置のプロ、り図
、第6図は自動しきい値制御回路図、M7図は第6図の
動作を示す波形図、第8図は反射光の影響を示す波形図
である。 l:発光部、la:発光素子、lC:駆動回路、2:受
光部、2a:受光素子、2c:増幅回路、2d:2値化
回路、3 : ’l’lカーラ、5:自動利得制御回路
。 第4図 第5図 第6図
@Figure 1 is a professional diagram showing an embodiment of this invention, Figure 2,
FIG. 23 is a circuit diagram showing a specific example of an amplifier circuit and an automatic gain control circuit, FIG. 6 is an automatic threshold control circuit diagram, FIG. M7 is a waveform diagram showing the operation of FIG. 6, and FIG. 8 is a waveform diagram showing the influence of reflected light. l: light emitting section, la: light emitting element, lC: drive circuit, 2: light receiving section, 2a: light receiving element, 2c: amplifier circuit, 2d: binarization circuit, 3: 'l'l curler, 5: automatic gain control circuit. Figure 4 Figure 5 Figure 6

Claims (1)

【特許請求の範囲】[Claims] 1)伝送用光ファイバと結合されかつ第1および第2の
光ファイバにより発光素子および受光素子とに結合され
るTカプラと、送信信号を駆動回路を介して前記発光素
子に入力して作動させる発光部と、前記発光素子の出力
を増幅回路を介して2値化回路に入力し2値化して受信
信号として出力する受光部とからなる双方向光信号伝送
装置において;前記送信信号と同期してこの送信信号が
高レベルの時に前記増幅回路の増幅度を下げる自動利得
制御回路を設けたことを特徴とする双方向光信号伝送装
置。
1) A T-coupler coupled to a transmission optical fiber and coupled to a light emitting element and a light receiving element through first and second optical fibers, and inputting a transmission signal to the light emitting element via a drive circuit to operate it. In a bidirectional optical signal transmission device comprising a light emitting section and a light receiving section that inputs the output of the light emitting element to a binarization circuit via an amplifier circuit, binarizes it, and outputs it as a received signal; A bidirectional optical signal transmission device comprising an automatic gain control circuit that lowers the amplification degree of the amplifier circuit when a transmission signal of the lever is at a high level.
JP60221177A 1985-10-04 1985-10-04 Two-way optical signal transmitter Pending JPS6281829A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP60221177A JPS6281829A (en) 1985-10-04 1985-10-04 Two-way optical signal transmitter

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP60221177A JPS6281829A (en) 1985-10-04 1985-10-04 Two-way optical signal transmitter

Publications (1)

Publication Number Publication Date
JPS6281829A true JPS6281829A (en) 1987-04-15

Family

ID=16762682

Family Applications (1)

Application Number Title Priority Date Filing Date
JP60221177A Pending JPS6281829A (en) 1985-10-04 1985-10-04 Two-way optical signal transmitter

Country Status (1)

Country Link
JP (1) JPS6281829A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6075635A (en) * 1995-12-28 2000-06-13 Lucent Technologies Inc. Bidirectional optical transceiver assembly

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS54140406A (en) * 1978-04-18 1979-10-31 Honeywell Inf Systems Data transmitter*receiver

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS54140406A (en) * 1978-04-18 1979-10-31 Honeywell Inf Systems Data transmitter*receiver

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6075635A (en) * 1995-12-28 2000-06-13 Lucent Technologies Inc. Bidirectional optical transceiver assembly

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