JP2997597B2 - Optical transceiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical transceiver and, more particularly, to an optical transceiver used for two-way communication.

[0002]

2. Description of the Related Art FIG. 3 is a block diagram showing the configuration of a conventional optical transceiver. In FIG. 3, reference numerals 1 and 10 denote input terminals to which an input signal of an electric signal is input, and reference numerals 2 and 11 denote input terminals 1 and 2.
An input interface circuit for converting an input signal input from 10 into a level suitable for handling in the optical transceiver;
Reference numerals 3 and 12 denote light-emitting element driving circuits for driving the next-stage light-emitting elements 4 and 13; 4, 13 light-emitting elements for converting an input signal from an electric signal to an optical signal; The optical transmission lines 6 and 15 are light receiving elements for converting optical signals transmitted through the optical transmission lines 5 and 14 into electric signals, and the light receiving elements 7 and 16 are converted by the light receiving elements 6 and 15. An amplifier that amplifies electrical signals to an appropriate level,
Reference numerals 8 and 17 denote output interface circuits for converting the electric signals amplified by the amplifiers 7 and 16 to a level suitable for the output terminal and outputting the converted signals. An output terminal for outputting an electric signal as an output signal.

The light-emitting elements 19 and 20 detect the light levels of the light signals received by the light-receiving elements 15 and 6, output monitor signals (light intensity signals), and control the light-emitting element driving circuits 3 and 12. A light receiving level monitor circuit for controlling the light emitting levels of the light emitting elements 4 and 13 and 21 and 22 are amplifiers 1
This is a monitor signal detection circuit that receives outputs from 6, 7 and detects a monitor signal in the electric signal.

Next, the operation will be described. The optical transceiver shown in FIG. 3 performs bidirectional optical communication. Here, for the sake of simplicity, the communication path from the input terminal 1 to the output terminal 9 is defined as the direction A,
The communication path in the direction from the input terminal 10 to the output terminal 18 is B
The direction will be described. First, an operation of an input signal (main signal) input from the input terminal 1 will be described. An input signal, which is an electric signal, is input to an input terminal 1 and then input to an input interface circuit 2 to be converted to an appropriate level. Next, the main signal is output to the light emitting element driving circuit 3, the light emitting element 4 is driven, the main signal is converted into an optical signal, sent to the light receiving element 6 through the optical transmission line 5, and then the amplifier 7 After being amplified to an appropriate level, it is output to an output terminal 9 through an output interface circuit 8.

Here, the light level of the light signal incident on the light receiving element 6 is detected by a light receiving level monitor circuit 20, and the monitor signal from the light receiving level monitor circuit 20 is B
The signal is output to the light emitting element drive circuit 12 along the path in the direction. The monitor signal is combined with the main signal of the path in the direction B by the light emitting element drive circuit 12 and output to the light emitting element 13 to control the light emission level of the light emitting element 13. The optical signal output from the light emitting element 13 is output to the light receiving element 15 through the optical transmission line 14, where it is converted into an electric signal. This electrical signal is input to an amplifier 16 where it is amplified to an appropriate level. At this time, the monitor signal detection circuit 21 receives the output of the amplifier 16, detects the monitor signal in the direction A combined with the main signal in the path in the direction B, and outputs this to the light emitting element drive circuit 3. Thus, the light emission level of the light emitting element 4 in the A direction is controlled. In this way, by controlling the light emission level in the other direction by the monitor signal and also controlling the light emission level in the own direction, the output of the light emitting element 4 is controlled to keep the light level incident on the light receiving element 6 constant. are doing.

The method of controlling the light receiving element 15 in the B direction is also performed by using the light receiving level monitor circuit 19 and the monitor signal detecting circuit 22, as in the case of the A direction described above.

[0007]

Since the conventional optical transceiver is configured as described above, even when there is no main signal, the light emitting element operates under feedback control by the monitor signal of the optical level, and operates. Since unnecessary optical transmission and reception are performed, there is a problem that the life of the light emitting element is shortened.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and when there is no main signal, the transmission light level is controlled to reduce unnecessary light transmission and reception, and the life of the light emitting element is reduced. An object is to obtain an optical transceiver that can be lengthened.

[0009]

SUMMARY OF THE INVENTION An optical transceiver according to the present invention is used as a pair and performs bidirectional optical communication between each other.
An optical transceiver, which is the light emitting element of the other optical transceiver
The optical signal emitted from the device is received, and the received optical signal is
A light receiving element for converting an output signal of the electrical signal, the light receiving element
In detecting the light level of the received light signal, and the light receiving level detection means you output signal <br/> No. as a first monitor signal detected this, and inputs the drive signal, the drive to be the input Light signal
A light-emitting element that converts it into a signal and emits it,
A first main signal which is an input signal to be detected and the light receiving level detection
And synthesizing the first monitor signal output from the means.
A driving signal is input to the light emitting element based on the synthesized signal.
Light emitting element driving means, and an output converted by the light receiving element.
A second monitor signal which is a signal obtained by detecting a light level of an optical signal received by a light receiving element of an optical transceiver of the other party from the signal.
Detects, the light emitting element of the second monitor signal detected this
A monitor signal detection means for controlling the light emission level of said light emitting element and outputs the child drive means, or the monitor signal detection means
Monitor signal output to the light emitting element driving means from the
And operation switching means that controls whether to operate the light emitting element by ON / OFF, and detects the presence or absence of the first main signal, is converted by the light receiving element
Input signal to the other party's optical transceiver in the output signal
The presence or absence of a second main signal is detected, and the first main signal is detected.
Signal and / or any of the second main signals
Is detected, the operation switching means
Operating the light emitting element, the first main signal, and
Wherein when none of the second main signal that there is no is detected, it is desirable to make not operated by Ri said light emitting element to the operation switching means.

Furthermore, the optical transceiver according to the invention, in the optical transceiver, instead of the operation switching means, the light emitting element drive means from the monitor signal detection means
Amplifies the second monitor signal output to the predetermined level to a predetermined level.
It has a magnification switching unit that, said main signal detecting means, before
Serial first main signal, and one of the second main signal or
If either it is not is detected, Ri by the magnification switching unit, the calling from the monitor signal detection means
A second monitor signal output to the optical element driving means which is amplified to shall to a predetermined level.

[0011]

The optical transmitter / receiver of the present invention detects the transmission / reception bidirectional main signal so that when there is no bidirectional main signal, the light emitting element is not operated and the optical communication is not performed. Thus, the life of the light emitting element can be extended.

In addition, the optical transceiver according to the present invention detects the transmission / reception bidirectional main signal and controls the transmission light level of the light emitting element except for the case where there is a bidirectional main signal, thereby eliminating unnecessary transmission. By preventing optical communication, the life of the light emitting element can be extended.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of an optical transceiver according to an embodiment of the present invention. In the drawing, the same reference numerals as those in FIG. 3 denote the same or corresponding parts. In FIG. 1, reference numerals 23 and 24 denote main signal detection circuits for detecting main signals from the input interface circuits 2 and 11 and output interface circuits 8 and 17, and reference numerals 25 and 26 switch according to the outputs of the main signal detection circuits 23 and 24. Turn on the element drive circuits 3 and 12 and O
This is a drive circuit switching circuit for performing FF.

Next, the operation will be described. The main signal detection circuit 23 detects the main signal based on the input / output signals of the input interface circuit 2 and the output interface circuit 17. If the main signal is not detected by the interface circuits 2 and 17, the drive circuit switching circuit 25 is activated. The light emitting element driving circuit 3 is turned off to stop the operation, and the light emitting element 4 is not caused to emit light.

On the other hand, when a main signal is detected in one or both of the input and output signals of the input interface circuit 2 and the output interface circuit 17, the driving circuit switching circuit 25 is operated to drive the light emitting element driving circuit 3. The light emitting element 4 emits light in the same manner as in the conventional example,
It operates so that the light level incident on the light receiving element 6 becomes constant. Similarly, the main signal detection circuit 24 and the drive switching circuit 26 also turn on or off the light emitting element drive circuit 12 depending on whether a main signal is detected in the input / output signals of the input interface circuit 11 and the output interface circuit 8. The light emitting element 13 emits light or does not emit light.

As described above, the operation of the light emitting element drive circuit for controlling the light emitting element is controlled by detecting whether or not there is a main signal in the input / output signals of the input and output interface circuits. Since the light emitting element is not operated when there is no main signal, it is possible to prevent the life of the light emitting element from being shortened by performing unnecessary communication.

In the above embodiment, the drive signal switching circuits 25 and 26 are provided in the monitor signal detection circuits 21 and 22. However, instead of the drive circuit switching circuits 25 and 26, a light level monitor signal is provided. Even when a circuit for switching the amplification factor is provided, the same effect as in the above embodiment can be obtained. This will be described below as another embodiment.

FIG. 2 is a block diagram showing the configuration of an optical transceiver according to another embodiment of the present invention. In FIG. 2, the same reference numerals as in FIG. 1 denote the same or corresponding parts. In FIG. 2, reference numerals 27 and 28 denote amplification factor switching circuits that multiply the monitor signal of the light level detected by the monitor signal detection circuits 21 and 22 by x times and output the multiplied signals to the light emitting element drive circuits 3 and 12.

Next, the operation will be described. The main signal detection circuit 23 detects whether or not there is a main signal in the input / output signals of the input interface circuit 2 and the output interface circuit 17. If the main signals are detected in both interface circuits 2 and 17, the monitor signal detection is performed. Without amplifying the monitor signal of the light level detected by the circuit 21, that is,
Assuming that the amplification factor x is 1, it is output to the light emitting element drive circuit 3 as it is, and is operated so that the level incident on the light receiving element 6 becomes constant as in the conventional example.

On the other hand, when there is no main signal in both interface circuits 2 and 17, or when only one signal has a main signal, the amplification factor switching circuit 27 is operated to detect the light level detected by the monitor signal detection circuit 21. Is multiplied by x and output to the light emitting element drive circuit 3. In the light emitting element driving circuit 3 to which the monitor signal multiplied by x is output, the light emitting level of the light emitting element 4 is reduced by 1 / x by the feedback operation.
Unnecessary light emission in the light emitting element 4 is prevented by suppressing the light emission to twice. Similarly, the main signal detection circuit 24 and the amplification factor switching circuit 28 also detect the light detected by the monitor signal detection circuit 22 depending on whether the main signal is detected in the input / output signals of the input interface circuit 11 and the output interface circuit 18. Level monitor signal or x
The output is multiplied and output to the light emitting element drive circuit 12 so that the light emitting element 13
By controlling the light emission intensity of 1 / x to 1 / x, the operation is the same as in the conventional case when there is a main signal, and the transmission signal without the main signal can be transmitted down to the 1 / x light emission level. I have.

As described above, by detecting whether or not there is a main signal in the input and output signals of the input and output interface circuits, the amplification factor of the monitor signal of the light level output to the light emitting element driving circuit for controlling the light emitting element is detected. , Thereby controlling the light emission level of the light emitting element. Therefore, when there is no main signal in both directions, the light emission level of the light emitting element can be suppressed to a low level. Can be prevented from shortening the life of the camera.

[0022]

As described above, according to the optical transmitter / receiver according to the present invention, the operation of the light emitting element drive circuit for controlling the light emitting element is controlled by detecting the transmission / reception bidirectional main signal. In the case where there is no main signal, the light emitting element is not operated. Therefore, by preventing unnecessary communication, the life of the light emitting element can be extended.

Further, by detecting the main signal in the transmission and reception directions, the amplification factor of the monitor signal of the light level output to the light emitting element driving circuit for controlling the light emitting element is controlled, thereby controlling the light emitting level of the light emitting element. Therefore, when there is no main signal in two directions, or when there is no main signal in one direction, the light emission level of the light emitting element can be suppressed to a low level. There is an effect that the life can be prevented from being shortened. .

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an optical transceiver according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of an optical transceiver according to another embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of a conventional optical transceiver.

[Explanation of symbols]

 1,10 input terminal 2,11 input interface circuit 3,12 light emitting element drive circuit 4,13 light emitting element 5,14 optical transmission line 6,15 light receiving element 7,16 amplifier 8,17 output interface circuit 9,18 output terminal 19 , 20 light reception level monitor circuit 21, 22 monitor signal detection circuit 23, 24 output signal detection circuit 25, 26 drive circuit switching circuit 27, 28 amplification factor switching circuit

Claims (2)

(57) [Claims] Used in claim 1] pair meet optical transceiver for bidirectional optical communication between each other, the optical signal emitted from the light emitting element of the optical transceiver of the other party
Received light, and converts the received optical signal into an electrical signal output signal.
And conversion to the light receiving element detects the optical level of the optical signal received by the light receiving element, a light receiving level detection means that to output the detected signal of this <br/> as a first monitor signal, a drive signal Input, and the input drive signal is converted to an optical signal.
A light emitting element that converts and emits light, and a first main signal that is an input signal input as an electric signal and
A first monitor signal output from the light receiving level detecting means
And the driving signal is calculated based on the synthesized signal.
The light emitting element driving means input to the light emitting element and the output signal converted by the light receiving element are used to transmit the light
Detects the optical level of the optical signal received by the light receiving element of the receiver
Detecting a second monitor signal is a signal was detected in this
Outputting a second monitor signal to the light emitting element driving means;
A monitor signal detection means for controlling the light emission level of the serial light-out the light emitting element drive means from the monitor signal detection means
By turning on / off the second monitor signal
And behavior switching means Ri that control whether to operate the light emitting element, and detects the presence or absence of the first main signal, the light receiving
Optical transmission / reception of the other party in the output signal converted by the element
The presence or absence of the second main signal, which is the input signal to the detector,
Any one of the first main signal and the second main signal or
If both are detected, the operation is turned off.
Operating the light emitting element by the switching means,
Main signal, and when none of the second main signal that there is no is detected, a main signal detecting means so as not to operate the Ri by said operation switching means and the <br/> emitting element
Optical transceiver, characterized in that it includes. 2. An optical transceiver according to claim 1, wherein a second monitor output from said monitor signal detecting means to said light emitting element driving means is used instead of said operation switching means.
Has a magnification switching unit that amplifying the data signal to a predetermined level, said main signal detecting means, the first main signal, and one or both is not that detection of the second main signal If it is, the Ri by the magnification switching unit, the monitor
Output from the data signal detecting means to the light emitting element driving means.
Optical transceiver, wherein the is <br/> that amplifies the second monitor signal to a predetermined level.