JPH06252853A - Spatial optical transmission communication equipment - Google Patents

Abstract

PURPOSE:To reduce power consumption by keeping a proper output for a light emitting element so as to prevent deterioration in the characteristic and the service life even when a communications range and environment or the like are changed. CONSTITUTION:An optical signal 14 transmitted from an opposite station is received by a light receiving element 15 and converted into an electric signal and inputted to an amplifier 16. The amplifier 16 amplifies the received signal and outputs a level signal indicating the strength of the received signal to a discrimination control circuit 17. The discrimination control circuit 17 discriminates the level of the received signal and when the received optical signal 14 is weak, the output of a drive circuit 11 is increased and when the received optical signal 14 is strong, the output of the drive circuit 11 is decreased. Thus, an optical signal 13 outputted from the light emitting element 12 is always kept to a proper level even when the communications range and the environment or the like are subject to change.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spatial transmission optical communication device for performing bidirectional optical communication using an atmospheric space as a transmission medium.

[0002]

2. Description of the Related Art A two-way spatial transmission optical communication device using a spatial transmission system is composed of a light transmitter and a light receiver and performs optical communication by utilizing the atmospheric space as a transmission medium. It is configured as shown in FIG. That is, the light transmitter inputs the signal to be transmitted to the drive circuit 1 to input the light emitting element 2
To generate an optical signal and send it to the partner station using the atmospheric space as a transmission medium. Further, the light receiver receives the optical signal sent from the partner station by the light receiving element 3 to convert it into an electric signal, and amplifies it by the amplifier circuit 4 capable of controlling the gain.

In the above structure, the optical signal output from the light transmitter is usually set to a maximum value in order to obtain a longer transmission distance and better characteristics. And the receiver is
The dynamic range is ensured by using a circuit that changes the gain according to the level of the received signal to obtain an appropriate reception level.

However, in an actually operated system,
It is rare to use the performance limits of the device and communicate at a value well above the required light output. here,
If the light transmission output is changed so that the signal transmission level is lowered to the required level, communication may not be possible depending on the space condition. Therefore, it is not preferable to reduce the light transmission output.

Furthermore, in mobile communication, it is necessary to constantly output a light-transmitting output sufficient to ensure communication at the maximum distance of movement. Therefore, when the communication distance becomes the shortest, the light receiving device has a very large light receiving level, so that the gain to be amplified is limited and an appropriate receiving level is set. As a result, the light emitting element is always subjected to the maximum load, which not only deteriorates the characteristics and shortens the life, but also maximizes the power consumption.

[0006]

As described above, in the conventional space transmission optical communication device, the output of the light transmitter is made constant at the maximum point, and the amplification gain of the light receiver is adjusted and controlled to thereby increase the dynamic range. We have ensured that the equipment is versatile and flexible, and that it is also compatible with communication with mobile units.

However, the output of the light emitting element is always loaded with a maximum load regardless of whether it is necessary or not, which not only leads to deterioration of characteristics and life, but also has a drawback that power consumption becomes a maximum value.

The present invention has been made in view of the above circumstances. Even when the communication distance, environment, etc. change, the light emitting element is maintained at an appropriate output, deterioration of characteristics and life is prevented, and power consumption is reduced. It is an object to provide a space transmission optical communication device to be obtained.

[0009]

Means for Solving the Problems (First Invention)

According to the present invention, in a spatial transmission optical communication device in which an own station and an opposite station are installed with an atmospheric space as a transmission medium and bidirectional optical communication is performed, a light emitting element for sending an optical signal to the opposite station, and this light emission. A drive circuit for driving the element, a light receiving element for receiving the optical signal sent from the opposite station, an amplifier circuit for amplifying the signal received by this light receiving element, and the level of the above received signal is determined and the level is determined according to the level. And a determination control circuit that controls the output signal of the drive circuit and holds the optical signal output from the light emitting element at an appropriate level. (Second invention)

According to the present invention, in a space transmission optical communication device in which an own station and an opposite station are installed with an atmospheric space as a transmission medium, and one or both stations move to perform optical communication, an optical signal is sent to the opposite station. A light emitting element, a drive circuit for driving the light emitting element, an input circuit for fetching position information indicating the current position of the own station and the current position of the opposite station, and presets corresponding to the current positions of the own station and the opposite station With reference to the storage means for storing the value, the current positions of the own station and the opposite station, and the value stored in the storage circuit, the optical signal output from the light emitting element is determined according to the relative distance between the own station and the opposite station. And a light receiving element for receiving the optical signal sent from the light emitting element of the opposite station, and an amplifier circuit for amplifying the signal received by the light receiving element. (Third invention)

According to the present invention, in a space transmission optical communication device in which an own station and an opposite station are installed with an atmospheric space as a transmission medium, and a two-way optical communication is performed, a light emitting element for sending an optical signal to the opposite station and a communication device are used. A drive circuit for driving the light emitting element based on data, a light receiving element for receiving an optical signal sent from the opposite station, an amplifier circuit for amplifying a signal received by the light receiving element, and a signal received by the light receiving element Level determining circuit for determining the level of the signal, means for adding control data for controlling the optical transmission level of the opposite station to the communication data according to the determination result of the level determining circuit, and the control data in the received signal It is characterized by comprising means for controlling the drive signal level of the light emitting element and holding the optical signal output from the light emitting element at an appropriate level.

[0013]

[Operation] (First invention)

The optical signal sent from the opposite station is received by the light receiving element and converted into an electric signal. The level of the signal received by the light receiving element is determined by the determination control circuit, and the output signal of the drive circuit is controlled based on the determination result. That is, when the received light signal is weak, the output of the drive circuit is increased by the output of the determination control circuit, and when the received light signal is strong, the output of the drive circuit is reduced. As a result, even if the environment or the like changes, communication can be performed with an optical signal of an appropriate level. (Second invention)

When performing communication, the position information of the own station and the position information of the opposite station are input to the control circuit via the input circuit. Based on the above position information, the control circuit refers to the information stored in the storage circuit to obtain the relative positional relationship between the own station and the opposite station, and outputs the optimum optical signal output from the own station based on the relative distance. Is calculated and the drive circuit is controlled. That is, when the control circuit determines that the relative distance between the own station and the opposite station is long, the control circuit controls the drive circuit so that the light output is increased, and When it is determined that the relative distance is short, the drive circuit is controlled so that the light output is reduced. As a result, even if the communication distances of both stations change, it is possible to always output the optical signal at an appropriate level. (Third invention)

The optical signal sent from the opposite station is received by the light receiving element, converted into an electrical signal and input to the level determination circuit. This level judgment circuit judges the level of the received signal, and when the optical signal from the opposite station is weak, outputs control data to increase the light output of the opposite station. When the signal is strong, control data that reduces the light output of the opposite station is output. This control data is added to the communication data and transmitted to the opposite station.

The control data added to the communication data is separated on the receiving side and analyzed to recognize the light output level required by the opposite station. A control signal is sent to the drive circuit based on the recognized level, and the level of the optical signal output from the light emitting element is controlled. As a result, the optical signal can be transmitted at the output of the proper level required by the opposite station.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 is a block diagram showing the structure of a spatial transmission optical communication device according to the first embodiment of the present invention, in which the local station and the opposite station have the same structure.

As shown in FIG. 1, the light transmitter inputs a signal to be transmitted to a driving circuit 11 to drive a light emitting element 12 such as a light emitting diode or a laser diode, and generates an optical signal 13 to generate an atmospheric space. It is sent to the opposite station as a transmission medium. Further, the light receiver receives the optical signal 14 sent from the opposite station by the light receiving element 15 and converts it into an electric signal, and the amplifier circuit 16
To enter. The amplifier circuit 16 amplifies the received signal and outputs a level signal indicating the strength of the received signal to the determination control circuit 17. The determination control circuit 17 determines the level of the received signal, controls the drive circuit 11 according to the level, and outputs the optical signal 1 output from the light emitting element 12.
Control strength of 3.

In the above structure, the optical signal 14 sent from the opposite station is received by the light receiving element 15, converted into an electric signal and input to the amplifier 16. This amplifier 16
Amplifies the received signal and outputs a level signal indicating the strength of the received signal to the determination control circuit 17. The judgment control circuit 17 judges the level of the received signal and controls the output signal of the drive circuit 11 based on the judgment result. That is, when the received optical signal 14 is weak, the output of the drive circuit 11 is increased by the output of the determination control circuit 17, and when the received optical signal 14 is strong, the output of the drive circuit 11 is output by the output of the determination control circuit 17. The control is performed so as to reduce.

As a result, a signal can be transmitted with an appropriate level of optical output. Therefore, not only when the communication distance changes such as when communicating with a mobile station, but also when using fixed communication, the output is usually reduced, and when the atmospheric condition is poor, for example when fog occurs, the output is output. By increasing, the light emitting element 12 can be maintained at an appropriate output, deterioration of characteristics and life can be prevented, and power consumption can be reduced. (Second Embodiment) FIG. 2 is a block diagram showing the structure of a spatial transmission optical communication device according to the second embodiment of the present invention, in which both the own station and the opposite station have the same structure. In this second embodiment,
This shows the case where both the own station and the opposite station move on a predetermined track, for example, a mobile station provided in a train or the like.

In FIG. 2, reference numeral 21 denotes an input circuit of the light transmitter, which receives the position information 22 of its own station and the position information 23 of the opposite station. When the train is provided with a mobile station, the train is equipped with a distance accumulating device for accumulating the traveled distance. Therefore, the position of the own vehicle is recognized based on the distance data and used as the position information 22. In this case, in order to reduce the occurrence of error, correct position information is obtained by calibrating the distance data at the stop position at the train stop station. Then, the position information 22 of each train is transmitted to the partner station by wireless communication, thereby making the position information 23 of the opposite station. The position information sent to the partner station can be added to the optical signal. The input circuit 21 reads the position information 22 of the own station and the position information 23 of the opposite station, and outputs them to the control circuit 24.

Reference numeral 25 is a setting circuit for setting information corresponding to the positions of the own station and the opposite station. The information set by the setting circuit 25 is stored in the storage circuit 26. Based on the input positional information, the control circuit 24 refers to the information stored in the storage circuit 26 and determines the optimum optical signal output to be transmitted by the local station based on the relative positional relationship between the local station and the opposite station. Calculate and control the drive circuit 11. The drive circuit 11 drives the light emitting element 12 under the control of the control circuit 24, generates an optical signal 13, and sends it to the opposite station. Also, the light receiver is
The optical signal 14 sent from the partner station is received by the light receiving element 15, converted into an electric signal, and amplified by the amplifier circuit 16.

In the above configuration, the location information 22 of the own station
And the position information 23 of the opposite station is input to the control circuit 24 via the input circuit 21. The control circuit 24 obtains the relative positional relationship between the own station and the opposite station by referring to the information stored in the storage circuit 26 on the basis of the input position information 22 and 23, and the own station transmits from the relative distance. The optimum optical signal output to be calculated is calculated, and the drive circuit 11 is controlled.

That is, when the control circuit 24 determines that the relative distance between the own station and the opposite station is long, the drive circuit 11
When it is determined that the relative distance between the own station and the opposite station is short,
The drive circuit 11 is controlled such that the light output is small.

As a result, when the communication distance becomes shorter than the performance limit, the output of the light emitting element 12 is lowered, and when the communication distance becomes long, the output of the light emitting element 12 is maximized when used in a state close to the performance limit. Can be controlled. Therefore, even if the communication distance between the stations changes with the movement of the stations, the output of the light emitting element 12 can be properly maintained, communication can be reliably performed, deterioration of characteristics and life can be prevented, and power consumption can be reduced. Can be lowered.

In this embodiment, the case where both of the opposite stations are mobile stations has been described, but it is also possible to fix one station. In this case, the location information is information on the mobile station side. Need only be loaded, and the setting values need to be set and stored only for mobile station information.

For example, in an automatic warehouse, when articles are automatically stored and taken out by clay traveling on orbit, a fixed station gives a command to a crane as a mobile station by an optical signal. The crane detects a stop plate provided corresponding to each storage rack, obtains position information, and transmits the position information to a fixed station by wireless communication. On the fixed station side, the location information sent from the crane is used as the location information for the opposite station 2
Used as 3. As a result, even if the communication distance to the fixed station changes due to the movement of the crane, the output of the light emitting element can be properly maintained and the communication with the crane can be reliably performed.

Further, in this embodiment, the setting circuit 25 for setting the value corresponding to the position information of each station is provided. However, by fixing the setting value, the setting circuit 25 can be omitted and the setting circuit 25 can be omitted in advance. It is also possible to store the setting information in the memory circuit 26. Furthermore, when the relative distance to the opposite station becomes extremely large and communication becomes impossible, the light emission output may be turned off. (Third Embodiment) FIG. 3 shows the third embodiment of the present invention. FIG. 3 is a block diagram showing the configuration of a spatial transmission optical communication device according to a third example, in which the own station and the opposite station have the same configuration.

The communication data 31 is stored in the transmission buffer circuit 3
2 and is sent to the drive circuit 11. Drive circuit 1
1 drives the light emitting element 12 by the data from the transmission buffer circuit 32, generates the optical signal 13, and sends it to the opposite station. At this time, control data 33 for controlling the optical output of the opposite station is added to the optical signal 13 in addition to the communication data 31.

The optical signal 14 sent from the opposite station
Similarly, the control data is added to the communication data of the opposite station. The optical signal 14 from the opposite station is received by the light receiving element 15, converted into an electric signal, amplified by the amplification / reproduction circuit 34, and reproduced as data. The reproduced data is taken into the reception buffer circuit 35, and the part excluding the control data is output as the reception data 36. Further, the reception buffer circuit 35 analyzes the separated control data, recognizes the light output level required by the opposite station, and controls the drive circuit 11 by the control signal 37.

The output of the amplification reproduction circuit 34 is sent to the reception level determination circuit 38. The reception level determination circuit 38 determines whether or not the level of the optical signal 14 being received is proper, and the determination result is the control data 33.
To the transmission buffer circuit 32. The transmission buffer circuit 32 adds the control data 33 to the communication data 31 and outputs it to the drive circuit 11.

In the above configuration, when the optical signal 14 from the opposite station is weak, the reception level determination circuit 38 outputs control data 33 for increasing the light output of the opposite station, and the transmission buffer circuit 32 outputs the control data 33. It is added to the communication data 31 and transmitted to the opposite station. When the optical signal 14 from the opposite station is strong, the reception level determination circuit 38 outputs control data 33 for reducing the light output of the opposite station, and the transmission buffer circuit 32 adds the control data 33 to the communication data 31. And transmitted to the opposite station. As a result, the light output of the opposite station can be controlled.

Similarly, control data for controlling the light transmission output is added to the communication data and transmitted from the opposite station. This control data is separated from the communication data by the reception buffer circuit 35 and analyzed, the light output level required by the opposite station is recognized, and the drive circuit 1 outputs the control signal 37.
1 to control the output level of the optical signal 13.

As a result, the optical signal 13 can be transmitted with the output of the proper level required by the opposite station. That is, when used at a distance shorter than the performance limit, the light emitting element 1
The output of the light emitting element 12 can be controlled so that the output of the light emitting element 12 is maximized when it is used in a state close to the performance limit by reducing the output of No. 2 and maintaining the light emitting element 12 at an appropriate output, preventing deterioration of characteristics and life, and Power can be reduced. (Fourth embodiment)

FIG. 4 is a block diagram showing the structure of a spatial transmission optical communication device according to the fourth embodiment of the present invention, which has the same structure as both the own station and the opposite station. The communication data 31 is
The level is controlled by the level control circuit 41 and input to the synthesis circuit 42. The synthesis circuit 42 is a control circuit 41.
The communication data from the control station and the control data 43 for instructing the light transmission output of the opposite station are combined to drive the drive circuit 11, and the light emitting element 12 generates the optical signal 13 and sends it to the opposite station.

The optical signal 14 sent from the opposite station
Similarly, the control data is added to the communication data of the opposite station. The optical signal 14 from the opposite station is received by the light receiving element 15 and converted into an electric signal, and the amplifier circuit 1
After being amplified in 6, the distribution circuit 44 separates it into communication data 45 and control data 46. The separated communication data 45 is input to the reception level determination circuit 47, and the control data 46 is input to the control data determination circuit 48. The control data judgment circuit 48 judges the control data 46 and controls the output signal level of the level control circuit 41.

The reception level determination circuit 47 outputs the communication data 45 as reception data 49, determines the level of the input communication data 45, and inputs the signal reception level to the control data generation circuit 50. To do. The control data generation circuit 50 generates control data 43 for instructing the light transmission output of the opposite station according to the reception level of the signal and inputs it to the synthesis circuit 42. The synthesizing circuit 42 synthesizes the communication data from the level control circuit 41 and the control data 43 as described above, and outputs the synthesized data to the drive circuit 11.

In the above configuration, the optical signal 14 sent from the opposite station is converted into an electric signal by the light receiving element 15, amplified by the amplifier circuit 16, and then distributed by the distribution circuit 44 to the communication data 45 and the control data. 46, and the communication data 45 is sent to the reception level determination circuit 47. The reception level determination circuit 47 determines the level of the communication data 45 and notifies the control data generation circuit 50 of the level. The control data generation circuit 50 generates control data 43 instructing the light output of the opposite station according to the level of the received signal, and inputs the control data 43 to the synthesis circuit 42. That is, the control data generation circuit 50 controls the optical signal 14 received by the light receiving element 15.
If it is weak, the control data 43 for instructing the opposite station to increase the light transmission output is generated, and the received optical signal 14 is received.
If is strong, control data 43 for instructing the opposite station to reduce the light transmission output is generated. This control data 4
3 is combined with the communication data from the level control circuit 41 by the combining circuit 42 and transmitted to the opposite station. This allows
The light output of the opposite station can be controlled.

Similarly, since control data for instructing the light output level is sent from the opposite station, the distribution circuit 4
4, the control data 46 is separated, and the control data determination circuit 48
To enter. The control data determination circuit 48 determines the content of the control data 46 and controls the signal output level of the level control circuit 41. That is, the signal output level of the level control circuit 41 is controlled according to the instruction sent from the opposite station, and the optical signal 13 of the proper level required by the opposite station is sent out. As described above, the optical signal 13 can be transmitted at the output of the proper level required by the opposite station.

[0041]

As described above in detail, according to the present invention, the level of the received signal is judged to control the transmission output level. Therefore, when the communication distance changes, the atmospheric condition is bad, etc. Also, it is possible to keep the light emitting element at an appropriate output, prevent deterioration of characteristics and life, and reduce power consumption.

Further, according to the present invention, since the relative positional relationship between the own station and the opposite station is determined from the positional information of the own station and the opposite station, and the required light transmission amount is obtained to control the light transmission output, the station position and environment It is possible to keep the light emitting element at an appropriate output even when, etc. are changed.

Further, according to the present invention, in addition to the communication data, the data for controlling the light output of the opposite station is added to the data to be transmitted and transmitted, and the transmission output level is controlled on the receiving side according to the content of the control data received. At the same time, the control data for reducing or increasing the output of the opposite station is added to the communication data and transmitted depending on the level of the received optical signal, so that even if the communication distance, environment, etc. change. ,
The output of the light emitting element can be reliably maintained at an appropriate level.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of a spatial transmission optical communication device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing the configuration of a spatial transmission optical communication device according to a second embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of a spatial transmission optical communication device according to a third embodiment of the present invention.

FIG. 4 is a block diagram showing the configuration of a spatial transmission optical communication device according to a fourth embodiment of the present invention.

FIG. 5 is a block diagram showing a conventional space transmission optical communication device.

[Explanation of symbols]

 11 ... Driving circuit 12 ... Light emitting element 13 ... Optical signal 14 ... Optical signal 15 ... Light receiving element 16 ... Amplifying circuit 17 ... Judgment control circuit 21 ... Input circuit 22 ... Position information of own station 23 ... Position information of opposite station 24 ... Control Circuit 25 ... Setting circuit 26 ... Storage circuit 31 ... Communication data 32 ... Transmission buffer circuit 33 ... Control data 34 ... Amplification reproduction circuit 35 ... Reception buffer circuit 36 ... Reception data 37 ... Control signal 38 ... Reception level judgment circuit 41 ... Level Control circuit 42 ... Combining circuit 43 ... Control data 44 ... Distribution circuit 45 ... Communication data 46 ... Control data 47 ... Reception level determination circuit 48 ... Control data determination circuit 49 ... Reception data 50 ... Control data generation circuit

Claims (3)

[Claims] 1. In a spatial transmission optical communication device, in which an own station and an opposite station are installed with an atmospheric space as a transmission medium, and which performs bidirectional optical communication, a light emitting element for sending an optical signal to the opposite station, and the light emitting element A drive circuit for driving, a light receiving element for receiving an optical signal sent from the opposite station, an amplifier circuit for amplifying the signal received by this light receiving element, and a level of the above received signal is determined, and the above is determined according to the level. A spatial transmission optical communication device comprising: a determination control circuit that controls an output signal of a drive circuit and holds an optical signal output from the light emitting element at an appropriate level. 2. A light emitting element for transmitting an optical signal to an opposite station in a space transmission optical communication device in which an own station and an opposite station are installed with an atmospheric space as a transmission medium and one or both stations move to perform optical communication. A driving circuit for driving this light emitting element, an input circuit for fetching position information indicating the current position of the own station and the current position of the opposite station, and preset values corresponding to the current positions of the own station and the opposite station. By referring to the storage means for storing, the current positions of the own station and the opposite station, and the value stored in the above storage circuit, the optical signal output from the light emitting element is appropriate according to the relative distance between the own station and the opposite station. A spatial transmission light comprising a control circuit for controlling the level, a light receiving element for receiving an optical signal transmitted from a light emitting element of the opposite station, and an amplifier circuit for amplifying a signal received by the light receiving element. Communication Apparatus. 3. In a space transmission optical communication device in which an own station and an opposite station are installed with an atmospheric space as a transmission medium, and a two-way optical communication is performed, a light emitting element for sending an optical signal to the opposite station and communication data are used. A drive circuit for driving the light emitting element based on the light receiving element, a light receiving element for receiving the optical signal sent from the opposite station, an amplifier circuit for amplifying the signal received by the light receiving element, and a level of the signal received by the light receiving element. A level determination circuit for determining whether or not the light emitting element is in accordance with the control data in the received signal, and means for adding control data for controlling the optical transmission level of the opposite station according to the determination result of the level determination circuit to the communication data. Means for controlling the drive signal level of the light emitting element and holding the optical signal output from the light emitting element at an appropriate level. .