JPH0661947A - Optical space transmission system - Google Patents
Optical space transmission systemInfo
- Publication number
- JPH0661947A JPH0661947A JP4208720A JP20872092A JPH0661947A JP H0661947 A JPH0661947 A JP H0661947A JP 4208720 A JP4208720 A JP 4208720A JP 20872092 A JP20872092 A JP 20872092A JP H0661947 A JPH0661947 A JP H0661947A
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- Prior art keywords
- light emitting
- light
- emitting element
- optical
- output
- 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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Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は光空間伝送方式に係り、
特に光送信部より送出された光を受信部で受信して信号
を再生するとき、外来の光ノイズの影響を受けずに再生
することができるようにしたものに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical space transmission system,
In particular, the present invention relates to a device which, when receiving a light transmitted from an optical transmitter and reproducing a signal by a receiver, can reproduce the signal without being affected by external optical noise.
【０００２】[0002]
【従来の技術】光空間伝送では、光ファイバや光導波路
等の光信号用伝送媒体がないため、外来光がノイズとし
て光信号に乗り、データを破壊して再生不可能にする恐
れがある。そのため、従来では、この対策として本来の
データをキャリア変調して伝送している。2. Description of the Related Art In free-space optical transmission, since there is no optical signal transmission medium such as an optical fiber or an optical waveguide, extraneous light may enter the optical signal as noise and destroy the data to make it unreproducible. Therefore, conventionally, the original data is carrier-modulated and transmitted as a countermeasure.
【０００３】従来の光空間伝送方式を図３により説明す
る。光送信部Ｓには変調回路３１、ドライバ回路３２、
発光素子３３が設けられ、また光受信部Ｒには受光素子
３４、増幅回路３５、バンドパス・フィルタ３６、復調
回路３７が設けられている。A conventional optical space transmission system will be described with reference to FIG. The optical transmitter S includes a modulation circuit 31, a driver circuit 32,
A light emitting element 33 is provided, and a light receiving element R is provided with a light receiving element 34, an amplification circuit 35, a bandpass filter 36, and a demodulation circuit 37.
【０００４】変調回路３１に、図３（Ｂ）に示す如
き、伝送速度１０Ｋｂｐｓ（５ＫＨｚ）の「１」、
「０」の送信データが入力れると、これが同に示す如
く、５００ＫＨｚのキャリア周波数により変調される。
そしてこの変調波がドライバ回路１２に伝送されて送信
用の大きさに増幅され、発光素子３３に伝送されて光信
号に変換され出力される。As shown in FIG. 3B, the modulation circuit 31 has a transmission rate of 10 Kbps (5 KHz) of "1",
When the transmission data of "0" is input, it is modulated by the carrier frequency of 500 KHz as shown in FIG.
Then, this modulated wave is transmitted to the driver circuit 12, amplified to a size for transmission, transmitted to the light emitting element 33, converted into an optical signal, and output.
【０００５】この光信号は、受光素子３４により受信さ
れて電気信号に変換され、この変換された信号が増幅回
路３５で増幅され、バンドパスフィルタ３６に伝達され
る。そしてバンドパスフィルタ３６では５００ＫＨｚ信
号がバンドパスされて、図３（Ｂ）に示す如き信号が
出力され、これが復調回路３７に伝達されて、復調され
同に示す如き信号が再生データとして出力される。This optical signal is received by the light receiving element 34 and converted into an electric signal, and the converted signal is amplified by the amplifier circuit 35 and transmitted to the band pass filter 36. Then, the band-pass filter 36 band-passes the 500 KHz signal and outputs a signal as shown in FIG. 3B, which is transmitted to the demodulation circuit 37 and demodulated and a signal as shown is output as reproduction data. .
【０００６】[0006]
【発明が解決しようとする課題】ところで光信号の伝送
速度の上限は電気信号を光信号に変換する発光素子３３
および、光信号を電気信号に変換する受光素子３４の応
答速度により決定される。しかし、図３に示す如き従来
のものでは、送信データをキャリア変調することが必要
となるので、発光素子および受光素子が、前記の如く、
５００ＫＨｚの変換能力を持っていても、送信データの
伝送速度は５ＫＨｚ程度である。すなわち、電気信号→
光信号あるいは光信号→電気信号に変換する変換回路の
応答速度に比較して、送信データの伝送速度が数１０分
の１から数１００分の１程度に低下してしまうという欠
点が存在する。By the way, the upper limit of the transmission rate of an optical signal is the light emitting element 33 for converting an electric signal into an optical signal.
Also, it is determined by the response speed of the light receiving element 34 that converts an optical signal into an electric signal. However, in the conventional device as shown in FIG. 3, since it is necessary to perform carrier modulation on the transmission data, the light emitting element and the light receiving element are as described above.
Even if it has a conversion capability of 500 KHz, the transmission speed of transmission data is about 5 KHz. That is, electrical signal →
There is a drawback in that the transmission speed of transmission data decreases from several tenths to several hundredths as compared with the response speed of an optical signal or a conversion circuit for converting an optical signal into an electric signal.
【０００７】したがって本発明の目的は、このような問
題点を改善した光空間伝送方式を提供することである。Therefore, it is an object of the present invention to provide an optical space transmission system that solves the above problems.
【０００８】[0008]
【課題を解決するための手段】前記目的を達成するため
本発明では、図１（Ａ）示す如く、光送信部Ｓに第１ド
ライバ回路１１、第１発光素子１２、第２ドライバ回路
１３、第２発光素子１４、反転回路１５を設ける。また
光受信部Ｒに第１受光素子２１、第１増幅回路２２、第
２受光素子２３、第２増幅回路２４、電圧比較回路２５
を設ける。なお、第１発光素子１２は波長λ1 の光を出
力し、第２発光素子１４は波長λ2 の光を出力するもの
である。To achieve the above object, in the present invention, as shown in FIG. 1 (A), a first driver circuit 11, a first light emitting element 12, a second driver circuit 13 are provided in an optical transmission section S. The second light emitting element 14 and the inverting circuit 15 are provided. In the light receiving unit R, the first light receiving element 21, the first amplifying circuit 22, the second light receiving element 23, the second amplifying circuit 24, the voltage comparing circuit 25.
To provide. The first light emitting element 12 outputs light of wavelength λ 1 , and the second light emitting element 14 outputs light of wavelength λ 2 .
【０００９】[0009]
【作用】光送信部Ｓに、図１（Ｂ）に示す如き送信デ
ータが伝達されると、第１ドライバ回路１１と反転回路
１５に入力され、第１ドライバ回路１１はこれを送信レ
ベルの強さに強度変調し、これが第１発光素子１２によ
り波長λ1 の光信号に変換されて出力される。同時にこ
の送信データは、反転回路１５で反転されて図１（Ｂ）
に示す如きものとなり、これが第２ドライバ回路１３
により送信レベルの強さに強度変調され、第２発光素子
１４により波長λ2 の光信号に変換されて出力される。When the transmission data as shown in FIG. 1B is transmitted to the optical transmission section S, it is input to the first driver circuit 11 and the inverting circuit 15, and the first driver circuit 11 transmits this to the transmission level strong. Intensity modulation is performed, and this is converted into an optical signal of wavelength λ 1 by the first light emitting element 12 and output. At the same time, this transmission data is inverted by the inversion circuit 15 and is transmitted as shown in FIG.
And the second driver circuit 13
Is intensity-modulated by the intensity of the transmission level, converted by the second light emitting element 14 into an optical signal of wavelength λ 2 , and output.
【００１０】第１発光素子１２から出力された光信号
は、外来光ノイズにより図１（Ｂ）の如きものとな
り、第２発光素子１４から出力された光信号も、同様な
外来光ノイズにより同の如きものとなり、伝送され
る。The optical signal output from the first light emitting element 12 becomes as shown in FIG. 1B due to external optical noise, and the optical signal output from the second light emitting element 14 is also output due to similar external optical noise. And is transmitted.
【００１１】これらの光信号が、それぞれ第１受光素子
２１、第２受信素子２３により受信され、第１増幅回路
２２、第２増幅回路２４により増幅されて、図１（Ｂ）
、の如きものとなる。そしてこれらが電圧比較回路
２５に入力される。電圧比較回路２５は、例えば第１増
幅回路２２の出力電圧Ｖ1 が第２増幅回路２４の出力電
圧Ｖ2 よりも大きいＶ1 ＞Ｖ2 のとき「１」を出力する
ように構成されているので、これにより、図１（Ｂ）
の如き再生データが出力される。These optical signals are received by the first light receiving element 21 and the second receiving element 23, respectively, amplified by the first amplifying circuit 22 and the second amplifying circuit 24, and then, as shown in FIG.
, And so on. Then, these are input to the voltage comparison circuit 25. The voltage comparison circuit 25 is configured to output “1” when the output voltage V 1 of the first amplification circuit 22 is V 1 > V 2 which is larger than the output voltage V 2 of the second amplification circuit 24, for example. Therefore, this results in FIG.
Reproduced data such as
【００１２】このようにして送信データをキャリア変調
することなく、光空間伝送を可能にすることができるの
で、Ｅ→ＯおよびＯ→Ｅの各変換手段での応答速度でデ
ータ伝送可能となり、送信データの伝送速度をはるかに
向上させることができる。In this way, optical space transmission can be made possible without carrier-modulating the transmission data, so that data transmission becomes possible at the response speed in each conversion means of E → O and O → E, and transmission is performed. The data transmission rate can be greatly improved.
【００１３】[0013]
【実施例】本発明の一実施例を図２にもとづき説明す
る。図２において、他図と同符号部は同一部分を示し、
１６は第１自動パワーコントロール回路（ＡＰＣ）、１
７は第２ＡＰＣである。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to FIG. In FIG. 2, the same parts as in the other figures indicate the same parts,
16 is a first automatic power control circuit (APC), 1
7 is a second APC.
【００１４】第１発光素子１２は波長λ1 の光信号を出
力するものであり、第２発光素子１４は、この波長λ1
とは異なるもののこれとできるだけ近い値の波長λ2 の
光信号を出力するものである。これは、外来光ノイズが
各々の光信号に同様に乗るようにするためである。第１
受光素子２１には第１発光素子１２からの波長λ1 の光
信号のみを受信するために波長λ1 のみを受光する光学
フィルタを使用してもよい。同様に第２受光素子２３に
ついては波長λ1 を除去し波長λ2 を通過する光学フィ
ルタが使用できる。The first light emitting element 12 outputs an optical signal of wavelength λ 1 , and the second light emitting element 14 outputs the light signal of wavelength λ 1.
Although it is different from, it outputs an optical signal having a wavelength λ 2 having a value as close as possible to this. This is to allow external optical noise to be similarly carried on each optical signal. First
The light receiving element 21 may use an optical filter that receives only the wavelength λ 1 in order to receive only the optical signal of the wavelength λ 1 from the first light emitting element 12. Optical filter can be used to pass through the wavelength lambda 2 to remove the wavelength lambda 1 for the second light receiving element 23 as well.
【００１５】第１ＡＰＣ回路１６と第２ＡＰＣ回路１７
は、それぞれ第１発光素子１２の出力光と、第２発光素
子１４の出力光とが等しくなるように動作するものであ
る。図２の動作について説明する。First APC circuit 16 and second APC circuit 17
Respectively operate so that the output light of the first light emitting element 12 and the output light of the second light emitting element 14 are equal to each other. The operation of FIG. 2 will be described.
【００１６】いま、図１（Ｂ）に示す如き「１」、
「０」の送信データが光送信部Ｓに伝達されると、この
送信データは第１ドライバ回路１１と反転回路１５に入
力される。これにより反転回路１１から、図１（Ｂ）
に示す如き、データが出力される。Now, as shown in FIG. 1B, "1",
When the transmission data of “0” is transmitted to the optical transmission unit S, the transmission data is input to the first driver circuit 11 and the inverting circuit 15. As a result, the inverting circuit 11 outputs the signal shown in FIG.
The data is output as shown in.
【００１７】第１ドライバ回路１１により、前記送信デ
ータは光信号用に強度変調され第１発光素子１２を発光
させる。このとき、第１ＡＰＣ１６は、第１発光素子１
２の光出力が第２発光素子１４の光出力と等しくなるよ
うに、ドライバ回路１１を制御する。The transmission data is intensity-modulated for an optical signal by the first driver circuit 11 to cause the first light emitting element 12 to emit light. At this time, the first APC 16 is connected to the first light emitting device 1
The driver circuit 11 is controlled so that the light output of 2 becomes equal to the light output of the second light emitting element 14.
【００１８】第２ドライバ回路１２においても、同様
に、第２ＡＰＣ１７により、第２発光素子１４の光出力
が第１発光素子１２の光出力と等しくなるように制御さ
れる。第１発光素子１２の光信号は、図１（Ｂ）に示
す如き、外来光のノイズの影響を受けて送出される。同
様に第２発光素子１４の光信号は、図１（Ｂ）に示す
如き状態で送出される。このとき、これらの光信号に影
響を与えるノイズは同一である。Similarly, in the second driver circuit 12, the second APC 17 controls the light output of the second light emitting element 14 to be equal to the light output of the first light emitting element 12. The optical signal of the first light emitting element 12 is transmitted under the influence of the noise of the external light as shown in FIG. Similarly, the optical signal of the second light emitting element 14 is transmitted in the state as shown in FIG. At this time, the noise that affects these optical signals is the same.
【００１９】第１受光素子２１では、この波長λ1 の光
信号を受信して電気信号に変換し、これが第１増幅回路
２２で増幅され、図１（Ｂ）に示す如き出力電圧Ｖ1
となり、電圧比較回路２５に入力される。The first light receiving element 21 receives the optical signal of the wavelength λ 1 and converts it into an electric signal, which is amplified by the first amplifying circuit 22 and output voltage V 1 as shown in FIG. 1 (B).
And is input to the voltage comparison circuit 25.
【００２０】また第２受光素子２３では、この波長λ2
の光信号を受信して電気信号に変換し、これが第２増幅
回路２４で増幅され、図１（Ｂ）に示す如き出力電圧
Ｖ2となり、電圧比較回路２５に入力される。なお、前
記第１増幅回路２２、第２増幅回路２４の増幅率は、受
光素子から増幅回路出力までの電圧変換効率が等しくな
るように制御される。In the second light receiving element 23, this wavelength λ 2
1 is received and converted into an electric signal, which is amplified by the second amplifier circuit 24 and becomes an output voltage V 2 as shown in FIG. 1B, which is input to the voltage comparison circuit 25. The amplification factors of the first amplifier circuit 22 and the second amplifier circuit 24 are controlled so that the voltage conversion efficiency from the light receiving element to the amplifier circuit output becomes equal.
【００２１】電圧比較回路２５は、例えばＶ1 ＞Ｖ2 の
とき「１」を出力するように構成されているので、図１
（Ｂ）、の如き信号が入力されることにもとづき、
同の如き再生データを出力する。Since the voltage comparison circuit 25 is configured to output "1" when V 1 > V 2 , for example, FIG.
Based on the input of a signal such as (B),
The same reproduction data is output.
【００２２】[0022]
【発明の効果】本発明によれば送信データを差動送信
し、受信部でこれらを比較することによりデータの再生
を行っている。そのため外来光ノイズが各光信号に同様
に影響していれば、これを完全に打消すことができる。
したがって送信側でキャリア変調を行う必要がないの
で、電気信号を光信号に変換する変換手段および光信号
を電気信号に変換する変換手段の応答速度に応じた伝送
速度で光信号を伝送することができるので、従来のもの
に比較してはるかに速い伝送速度で光空間伝送を行うこ
とが可能となる。According to the present invention, transmission data is differentially transmitted, and the data is reproduced by comparing these in the receiving section. Therefore, if the external optical noise similarly affects each optical signal, it can be completely canceled.
Therefore, since it is not necessary to perform carrier modulation on the transmitting side, it is possible to transmit an optical signal at a transmission speed corresponding to the response speed of the conversion means for converting an electric signal into an optical signal and the conversion means for converting an optical signal into an electric signal. Therefore, it is possible to perform optical space transmission at a much higher transmission speed than the conventional one.
【図１】本発明の原理図である。FIG. 1 is a principle diagram of the present invention.
【図２】本発明の一実施例構成図である。FIG. 2 is a configuration diagram of an embodiment of the present invention.
【図３】従来例である。FIG. 3 is a conventional example.
１１ 第１ドライバ回路 １２ 第１発光素子 １３ 第２ドライバ回路 １４ 第２発光素子 １５ 反転回路 １６ 第１ＡＰＣ １７ 第２ＡＰＣ ２１ 第１受光素子 ２２ 第１増幅回路 ２３ 第２受光素子 ２４ 第２増幅回路 ２５ 電圧比較回路 11 1st driver circuit 12 1st light emitting element 13 2nd driver circuit 14 2nd light emitting element 15 Inversion circuit 16 1st APC 17 2nd APC 21 1st light receiving element 22 1st amplifier circuit 23 2nd light receiving element 24 2nd amplifier circuit 25 Voltage comparison circuit
Claims (4)
の光信号を受信して電気信号に変換して送信データを再
生する光空間伝送方式において、 光送信部に、 送信データを光信号に変換する第１発光素子（１２）
と、 送信データを反転する反転手段（１５）と、 この反転手段（１５）の出力データを光信号に変換する
第２発光素子（１４）を設け、 光受信部に、 前記第１発光素子（１２）の出力光を受光する第１受光
素子（２１）と、 前記第２発光素子（１４）の出力光を受光する第２受光
素子（２３）と、 これら第１発光素子（２１）の出力信号と第２受光素子
（２３）の出力信号とを比較する比較手段（２５）を設
け、 この比較手段（２５）より再生データを得るように構成
したことを特徴とする光空間伝送方式。1. An optical space transmission system in which an electric signal is converted into an optical signal and transmitted, and the optical signal is received and converted into an electric signal to regenerate transmitted data. First light emitting element (12) for converting into a signal
An inverting means (15) for inverting the transmission data and a second light emitting element (14) for converting the output data of the inverting means (15) into an optical signal are provided, and the first light emitting element ( 12) a first light receiving element (21) for receiving the output light, a second light receiving element (23) for receiving the output light of the second light emitting element (14), and outputs of these first light emitting element (21) An optical space transmission system characterized in that a comparison means (25) for comparing a signal with an output signal of the second light receiving element (23) is provided, and reproduction data is obtained from the comparison means (25).
子（１４）の出力光の波長を互いに異なるように構成し
たことを特徴とする請求項１記載の光空間伝送方式。2. The optical space transmission system according to claim 1, wherein the wavelengths of the output lights of the first light emitting element (12) and the second light emitting element (14) are different from each other.
素子（１４）の入力段にそれぞれドライバ手段を設け、
これらの各発光素子の出力光が同一の大きさになるよう
に各バライバ手段を制御することを特徴とする請求項１
記載の光空間伝送方式。3. A driver means is provided in each of the input stages of the first light emitting element (12) and the second light emitting element (14),
2. The variber means are controlled so that the output light of each of the light emitting elements has the same magnitude.
The optical space transmission method described.
素子（２３）にそれぞれフィルタを設け、第１受光素子
（２１）には、第１発光素子（１２）からの出力光のみ
を入力させ、第２受光素子（２３）には第２発光素子
（１４）からの出力光のみを入力させるように構成した
ことを特徴とする請求項１記載の光空間伝送方式。4. The first light receiving element (21) and the second light receiving element (23) are respectively provided with filters, and only the output light from the first light emitting element (12) is provided in the first light receiving element (21). 2. The optical space transmission system according to claim 1, wherein the second light receiving element (23) is configured to receive only the output light from the second light emitting element (14).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4208720A JPH0661947A (en) | 1992-08-05 | 1992-08-05 | Optical space transmission system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4208720A JPH0661947A (en) | 1992-08-05 | 1992-08-05 | Optical space transmission system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0661947A true JPH0661947A (en) | 1994-03-04 |
Family
ID=16560971
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4208720A Pending JPH0661947A (en) | 1992-08-05 | 1992-08-05 | Optical space transmission system |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0661947A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005151320A (en) * | 2003-11-18 | 2005-06-09 | Nec Viewtechnology Ltd | Light receiving device and optical communication system using it |
| US7248275B2 (en) | 2004-02-10 | 2007-07-24 | Alps Electric Co., Ltd. | Thermal head including Si substrate and method for manufacturing the same |
| JP2011239385A (en) * | 2010-05-07 | 2011-11-24 | Itt Manufacturing Enterprises Inc | Amplification of interleaved optical signals |
-
1992
- 1992-08-05 JP JP4208720A patent/JPH0661947A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005151320A (en) * | 2003-11-18 | 2005-06-09 | Nec Viewtechnology Ltd | Light receiving device and optical communication system using it |
| US7248275B2 (en) | 2004-02-10 | 2007-07-24 | Alps Electric Co., Ltd. | Thermal head including Si substrate and method for manufacturing the same |
| JP2011239385A (en) * | 2010-05-07 | 2011-11-24 | Itt Manufacturing Enterprises Inc | Amplification of interleaved optical signals |
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