JPS58209240A - Optical beam communicating method - Google Patents

Abstract

PURPOSE:To allow an inverse reflector of an opposite side to return an inverse reflecting optical beam in response only to a calling of a specific side, by providing an optical beam communication device tracking an angle of an optical axis of transmission/receiving automatically in the inverse reflector provided for the opposite side, for the own side. CONSTITUTION:On a two-axis movable stand 12 of the own ship, an optical beam transmission section 11 and a sighting TV camera 13 are provided. The oppsite ship is provided with an omnidirectional receiver 1 receiving optical beams transmitted and a photo diode 4 is fitted to receive the optical beam and to convert the beam into electric signals. The receiver 1 is controlled for the revolution with a potentiometer 3 and a motor 2 and the azimuth is changed. The optical beam detected at the photo diode 4 is photo-electric converted and transmitted to a code discriminating section 6, where a calling signal from the friend ships only is discriminated and transmitted to a storage section 5. Further, the inverse reflector 7 is provided, which is driven with an azimuth drive servo motor 8 and tracks with an output of the storage section 5 automatically.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a light beam communication method, and more particularly to a communication method for automatically tracking the optical axis of an original beam.

Conventionally, there is a method of communicating between ships using a light beam such as a laser beam. In this type of communication signal, it is necessary to automatically track the optical axis of the light beam. With conventional technology, a beam of light is reflected to the desired destination; a retroreflector such as a Nalenrekta is installed;
The light beam sent from your own ship is reflected by this retroreflector.
By receiving this reflected light on the own ship side, the own ship's transmitting and receiving optical axis automatically tracks the other ship.

With this technology, if the transmitting and receiving optical axis automatically tracks the retroreflector of the other ship in both azimuth and elevation, it is possible to maintain communication between the own ship and the other ship even if the own ship is slightly shaken.

However, if you scatter retroreflectors on a consort ship that is trying to communicate, that is, the other ship, there is an advantage in that a large amount of reflected light can be obtained when the optical axis is automatically tracked by the light beam, but on the other hand, it is also possible to receive retroreflectors from the enemy ship. The disadvantage is that the presence of the vessel is easily discovered optically.

Therefore, the object of the present invention is as follows: To provide a light beam communication method that eliminates the drawbacks of conventional techniques, exhibits retroreflection characteristics only in response to calls from a required transmission source, and makes it difficult for the presence of a retroreflector to be detected from sources other than the transmission source. It is in.

Thus, in the present invention, a light beam communication device is provided on the own side to automatically track the angle of the transmitting and receiving optical axis to a retroreflector installed on the other side, while an omnidirectional It includes a receiver, a storage means for sensing the calling direction and storing its azimuth, and means for directing the retroreflector in the calling direction. During communication, the omnidirectional receiver receives the light beam and stores the corresponding angle in the storage means. The output from the storage means automatically causes the retroreflector to track in the optical axis direction via the directing means. In this way, it is possible to obtain the effect that a retroreflector with a large reflection cross section is difficult to be detected by anyone other than the user.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram for explaining a method of optical beam communication between the own ship side and the other side. In this figure, a two-axis movable pedestal 12 is provided on the own ship side.

An optical beam transmitter 11 and an aiming TV left camera 3 are mounted on this biaxially movable pedestal 12. And a TV for pushing
The camera 13 is aimed in the direction of the opponent ship (consort ship), and the light beam is spread from the transmitter 11 and can be emitted at an angle θt. This light beam propagates through the atmosphere and reaches the other party's side. On the other hand, on the other party's ffl side, an omnidirectional receiver 1 is provided to receive the light beam sent from the own ship's side. A photodiode 4 is installed inside the omnidirectional receiver 1 to receive the original beam and convert it into an electrical signal. Further, the omnidirectional receiver 1 is controlled by a motor 2 via an azimuth detection potentiometer 3 so that it can rotate by 1 m, and its orientation can be changed. The direction detection potentiometer 3 is the omnidirectional receiver 3
Detects the azimuth of the light beam from the ship's own ship. The azimuth detected by the potentiometer 3 is stored in the storage section 5. Photo diode 4
The detected light beam is photoelectrically converted and sent to the code discriminator 6.
sent to. The code discrimination section 6 is a kind of enemy/friend identification device, and discriminates the code of only the calling signal from a friendly ship and sends it to the storage section 5.

A retroreflector 7 is provided on the other side In. In addition, omnidirectional receiver 1. The positional relationship between the retroreflector 7 and the radar mast 14 is as shown in FIG. 2, for example.

The retroreflector 7 is rotationally driven by an azimuth drive servo motor 8. An azimuth detection potentiometer 9 is attached to this rotation axis.
is provided to detect the azimuth of the retroreflector 7 and send its signal to the servo amplifier 10. On the other hand, the information is also sent to the servo amplifier 10 from the storage section 5 which stores the incident azimuth angle of the light beam. Then, the servo amplifier 10 rotates the servo motor 8 so that the difference between the azimuth from the storage section 5 and the azimuth given from the potentiometer 9 becomes zero. That is, when the difference between them becomes zero, the incident direction of the light beam and the direction in which the retroreflector 7 is facing coincide with each other.

In this state, a part of the light beam sent out from the light beam transmitting section 11 on the masochistic side is reflected by the retroreflector 7 and sent back to the own ship side. By receiving this reflected beam, the own ship can easily track the direction of the retroreflector 7 of the other ship.

In this embodiment, when the omnidirectional receiver 1 does not receive a light beam, that is, when it is in a standby state, the communication is stopped by a shielding object such as the retroreflector mast 14. Ru. This is achieved by initially installing the potentiometer 9 in the direction of the controller mast 14 in order to avoid communication with other than the intended ship.

As described above, according to the present invention, the light beam of one's own ship can easily visually track the other ship, and the retroreflector provided on the other ship emits a retroreflected light beam only to the specific ship called out. It can be returned.

[Brief explanation of drawings]

Fig. 1 is a diagram showing a communication system between one's own ship and the other ship to explain an embodiment of the present invention, and Fig. 2 is a diagram showing the communication system of the other ship, where (a) is a side view and (b) ) is a plan view. 111- is an omnidirectional receiver, 5 is an azimuth storage unit 10 is a servo amplifier, and 7 is a retroreflector. Agent De Physician Usuki 1) Toshiyuki

Claims (1)

[Claims] In a light beam communication method in which a light beam is transmitted from a light beam transmitter provided on a first side and automatically tracked by reflecting the light beam with a retroreflector provided on a second side, an omnidirectional receiver for receiving a light beam arriving from the first side; a storage means for storing the direction of arrival of the light beam received by the omnidirectional receiver; comprising directing means for directing the
A light beam communication method characterized by automatically tracking only the first side.