JPH01303820A - Light space transmission equipment - Google Patents

Abstract

PURPOSE:To detect the irradiation position of an optical beam with a high accuracy and to transmit information with a high grade, by a simple constitution as a whole by guiding a reflecting light beam to an observation optical system together with the optical beam folded and sent in parallel after an incident light beam is reflected with a half mirror. CONSTITUTION:An optical beam LA1 is reflected, made incident on an observation optical system 5 with a half mirror 31 arranged in the light flux of the optical beam LA1, and after an incident light beam LA5 is reflected by the half mirror 31, it is folded in parallel and made incident on the observation optical system 5. The incident light beam LA5 to come in the injection direction of the optical beam LA1 can be made incident on the observation optical system 5 in parallel to a reflecting light beam LA8 of the optical beam LA1. Thus, the same image as that when the return optical beam is suppressed and a light source 2 is arranged at the irradiated position by the optical beam can be obtained, the irradiated position by the optical beam can be detected with a high accuracy and the information can be transmitted with a high grade, by the easy constitution as a whole.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Industrial Application Field The present invention relates to an optical space transmission device, and is particularly suitable for application to an optical space transmission device configured to transmit information via a spatially transmitted light beam. It is.

B. Summary of the Invention The present invention provides an optical space transmission device in which an incident light beam is reflected by a half mirror disposed in the light beam of the light beam, and then the reflected light beam is folded back in parallel with the transmitted light beam. By guiding the light beam to the observation optical system, the irradiation position of the light beam can be detected with high precision with an overall simple configuration, and information can be transmitted with high quality.

C. PRIOR TECHNOLOGY Conventionally, in this type of spatial optical transmission device, the output azimuth of the light beam is adjusted with high precision so that the transmitted light beam reliably irradiates the receiving device.
In order to simplify such adjustment work, an optical space transmission device has been proposed in which the irradiation position of the light beam can be observed on the transmitting device side.

That is, in FIG. 2, 1 generally indicates a transmitting device of the optical space transmission device, and a laser light source 2 is disposed within a housing IA.

The laser light source 2 is configured to emit a light beam LAI modulated with a predetermined information signal through a large-diameter lens 3, thereby converting the light beam LA1 into a parallel light beam and sending it to a receiving device. It is done like this.

A telescope 5 is attached to the upper part of the housing IA, and is roughly adjusted so that the optical axis of the telescope 5 and the optical axis of the light beam LAI roughly coincide with each other.

Further, a collimating scope 11 is provided in front of the lens 3 and the telescope 5 to separate the light beam LAI and guide it to the telescope 5 parallel to the optical axis of the light beam LAI.

That is, the collimating scope 11
A part of the light beam LAI is received by a half mirror 12 arranged at an angle of approximately 45 degrees with respect to the optical axis of the mirror, so that the light beam LAI travels straight and is reflected at an angle of approximately 90 degrees. ing.

On the other hand, half mirror 13 is similar to half mirror 12.
The light LA2 reflected from the half mirror 12 is transmitted and guided to the corner cube prism 15.

The corner cube prism 15 is arranged so that the reflected light LA2 is incident on its entrance surface 15A, so that the reflected light LA3 whose optical axis is parallel to the reflected light LA2 is reflected by the corner cube prism 15. The beam is made incident on the half mirror 13.

Therefore, in the half mirror 13, the reflected light LA3
is reflected at an angle of approximately 90 degrees, and the reflected light LA4 is incident on the telescope 5.

In this way, the image of the laser light source 2 can be observed based on the reflected light LA4 incident on the telescope 5.

Furthermore, in the collimating scope 11, the telephoto ff1
A window 17 is provided on the front side of the laser beam a2, so that the image of the laser beam a2 and the side of the receiving device can be observed at the same time.

At this time, by holding the half mirrors 12 and 13 with high parallelism, even if the collimating scope 11 is arranged at an angle with respect to the optical axis of the light beam LAI (i.e., the half mirror 11 is not arranged at an angle of exactly 45 degrees with respect to the lens 3), a reflected light LA4 parallel to the optical axis of the light beam LA1 can be obtained.

Furthermore, by folding back the reflected light LA2 of the half mirror 12 via the corner cube prism 15, the collimating scope 11 changes the light beam L as shown by the arrow.
Even if it is twisted with respect to the optical axis of the AI,
Reflected light LA4 parallel to the optical axis of light beam LAI can be obtained.

Therefore, in the telescope 5, it is possible to obtain the reflected light LA4 as if it were emitted from the irradiation position of the light beam LAI,
As a result, the same image as when the laser light source 2 is placed at the irradiation position can be observed superimposed on the image on the receiver side, and thus the irradiation position of the light beam LAI can be reliably and easily determined on the transmitter 1 side. It can be confirmed.
-Therefore, the output azimuth angle of the light beam can be adjusted with an overall simpler configuration.

However, in the configuration shown in FIG.
and 13 must be maintained at a high degree of parallelism, and if the degree of parallelism goes out of order, the light beam LAI observed by the telescope 5 will change accordingly.
There was a problem that errors occurred in the irradiation position.

Furthermore, since the optical axes of the telescope 5 and the light beam LAI are separated by the distance HD (that is, there is parallax), the actual irradiation position and telephoto! There is a problem that an error inevitably occurs between the irradiation position and the irradiation position observed by Ji5.

As one method to solve this problem, as shown in FIG.
1 can be considered.

That is, the half mirror 21 is arranged at an angle of approximately 45 degrees with respect to the optical axis of the light beam LAI, and a part of the light beam LAI is reflected by the half mirror 21 and returned by the corner cube prism 15. .

As a result, the reflected light beam LA7 of the corner cube prism 15 passes through the half mirror 21 and is guided to the telescope 5 together with the incident light beam LA5 which enters the transmitter.

Therefore, by using the half mirror 21 and the corner cube prism 15 with high surface accuracy, the incident light beam LA5 whose optical axis is parallel to the optical axis of the light beam LAI is guided to the telescope 5 in parallel with the reflected light beam LA7. be able to.

In this way, the telescope 5 can obtain a reflected light beam LA7 that appears to have been emitted from the irradiation position of the light beam LA1, thereby producing an image similar to that obtained when the laser light source 2 is placed at the irradiation position without parallax. You can get it in any condition.

Furthermore, the reflected light beam LA reflected by the half mirror 21
6 is folded back parallel to the corner cube prism 15 and made to enter the telescope 5, even if the half mirror 21 is not held at an accurate 45 degree inclination, the light beam LAI can be emitted from the irradiation position. The reflected light beam LA7 can be obtained, and the irradiation position of the spectral beam can be confirmed with high precision.

D Problems to be Solved by the Invention However, in the configuration shown in FIG. 3, a part of the reflected light beam LA7 is reflected by the half mirror 21, so that the reflected light beam LA8 (hereinafter referred to as the returned light beam) There is a problem in that the light is fed back to the laser light source 2.

As a result, when a semiconductor laser is used as the laser light source 2, noise is mixed into the emitted light beam LAI,
It becomes difficult to transmit information with high quality.

Furthermore, by disposing, for example, a beam splitter between the laser light source 2 and the lens 3, and separating the incident light beam incident on the transmitting device from the light beam LAI and guiding it to the light receiving element, information can be transmitted and received between the transmitting and receiving devices. In a bidirectional optical space transmission device designed to do this, the emitted light beam LA1 is returned to the light receiving element, causing crosstalk in the information being sent and received, which ultimately makes it difficult to transmit information with high quality. becomes difficult.

The present invention has been made in consideration of the above points, and has an overall simple configuration, and is capable of optical space transmission that is capable of detecting the irradiation position of a light beam with high precision and transmitting information with high quality. This is an attempt to propose a device.

E Means for Solving Problem E In order to solve this problem, in the present invention, a light beam LAI modulated with an information signal is sent to a receiving device, so that the information signal can be transmitted to the receiving device via the light beam LAI. In the optical space transmission device 30 configured to transmit light beams to
1, an observation optical system 5 which receives the reflected light beam LA8 of the light beam LAI reflected by the half mirror 31, and an observation optical system 5 which receives the reflected light beam LA8 of the light beam LAI reflected by the half mirror 31; Incident light beam LA
An optical path folding optical system 15 is provided for folding back the reflected light beam LA9 of 5 in parallel to the optical axis of the reflected light beam LA9, transmitting it through a half mirror 31, and guiding it to the observation optical system 5.

A half mirror 31 disposed in the flux of the F action light beam LAI reflects the light beam LAI and makes it incident on the observation optical system 5, and after reflecting the incident light beam Lλ5 at the half mirror 31, it is turned back in parallel. By making the incident light beam LA5 enter the observation optical system 5, the incident light beam LA5 arriving from the exit direction of the light beam LAI is converted into a reflected light beam L of the light beam LAI.
It can be made to enter the observation optical system 5 parallel to A8.

In this way, the irradiation position of the light beam LA1 can be detected with high precision with an overall simple configuration.

At this time, by making the reflected light beam LA8 of the light beam LAI directly enter the observation optical system 5, the light beam L
For AI, the returning light beam can be suppressed.

G example An embodiment of the present invention will be described in detail below with reference to the drawings.

In FIG. 1, in which parts corresponding to those in FIG. A half mirror 31 is disposed at the rear end, and together with the corner cube prism 15 constitutes a collimating scope.

The half mirror 31 is machined with high surface precision and is designed to reflect approximately 172 times the amount of incident light, so that a part of the light beam LAI passes through the half mirror 31 and travels straight, A reflected light beam LA8 reflected by the half mirror 31 is made incident on the telescope 5.

In reality, optical systems such as telescopes are equipped with a lens on the entrance surface, so the amount of light beam reflected from the entrance surface and returned to the laser light source 2 via the half mirror 31 and the lens 3. can be reduced to an extremely small value.

Therefore, it is possible to suppress the returning light beam to a practically sufficient range, and it is possible to obtain a light beam LAI with less noise than in the past, thereby making it possible to transmit information with high quality.

On the other hand, the incident light beam LA5 that enters the transmitting device 30 from the emission direction of the straight-progressing light beam LAI is reflected by the half mirror 31 in the opposite direction to the reflected light beam LA8, and the reflected light beam LA9 is made incident on the corner cube prism 15.

Therefore, a reflected light beam LAIO whose optical axis is parallel to the reflected light beam LA9 is obtained via the corner cube prism 15, and the reflected light beam LAIO passes through the half mirror 31 and is incident on the telescope 5.

Thus, in the reflected light beam LAIO, the component of the incident light beam LA5 whose optical axis is parallel to the straight-progressing light beam LA1 becomes the reflected light beam LA8 of the light beam LAI.
The light beam L is incident on the telescope 5 in parallel with
Reflected light beam LA as if emitted from the AI irradiation position
You can get IO.

In this way, the same image as when the laser light source 2 is placed at the irradiation position can be observed superimposed on the image on the receiver side, and thus the irradiation position of the light beam can be reliably and easily confirmed on the transmitter 1 side. can do.

At this time, by arranging the half mirror 31 on the optical axis of the light beam LAI, it is possible to obtain a light beam that travels backwards from the irradiation position of the light beam LAI with respect to the light beam LAI, thereby reducing the parallax. It is possible to obtain a state without .

Furthermore, since it is only necessary to arrange one half mirror 31 on the optical axis of the light beam LAI, the overall configuration can be simplified compared to the conventional structure.

Furthermore, the reflected light beam LA reflected by the half mirror 31
9 is folded back parallel to the corner cube prism 15 and made to enter the telescope 5, the half mirror 21 is held at an accurate 45 degree inclination, and even if A reflected light beam LA10 as if emitted can be obtained.

Therefore, half mirror 31 and corner cube prism 1
5 with high surface accuracy, the irradiation position of the light beam can be confirmed with high precision.

In fact, since the half mirror 31 has a higher surface accuracy than the corner cube prism 15, in this case, the detection accuracy can be improved by increasing the machining accuracy of the corner cube prism 15. When using a corner cube prism 15 with an accuracy of 2 seconds within the practical range, the error could be suppressed to 9 [1] at a position 1 (km) away.

Furthermore, since the machining accuracy of the corner cube prism 15 only needs to be high, even if the entire collimating scope is arranged at an angle with respect to the optical axis of the light beam LAI, as shown by the arrow d, as shown by the arrow d. In this way, the irradiation position of the light beam can be confirmed with high precision even when the collimating scope is arranged twisted with respect to the optical axis of the light beam LAI, or even when the telescope 5 is arranged at an angle. be able to.

Thus, the corner cube prism 15 is a half mirror.
The reflected light beam L of the incident light beam LA5 reflected at 31
The telescope 5 configures an optical path folding optical system that folds back the reflected light beam LAIO parallel to the optical axis of the reflected light beam LA9, whereas the telescope 5 passes the reflected light beam LAIO that has been folded back by the optical path folding optical system through a half mirror 31. Configure the observation optical system to receive the data.

According to the above configuration, the half mirror 31 disposed on the optical axis of the light beam LAI reflects the light beam LAI and guides it to the telescope 5 (as well as the incident light beam LA5 reflected by the half mirror 31). By folding the reflected light beam LA9 in parallel using the corner cube prism 15 and guiding it to the telescope 5, the returning light beam can be suppressed simply by processing the half mirror 21 and the corner cube prism 15 with high surface precision. It is possible to obtain an image similar to that obtained when the light source 2 is placed at the irradiation position of the light beam LAI, and thus the irradiation position of the light beam can be detected with high precision and information with high quality can be obtained with an overall simple configuration. can be transmitted.

In the above-described embodiment, a case was described in which a collimating scope composed of a half mirror 31 and a corner cube prism 15 was used, but the present invention is not limited to this.
5 may be constituted by an integrated optical block.

Furthermore, in the above embodiment, the case where the half mirror 31 is arranged on the optical axis of the light beam LAI has been described, but the arrangement position of the half mirror 31 is not limited to the optical axis, but can be placed anywhere within the luminous flux of the light beam LAI. For example, the irradiation position of the light beam can be detected within a practically sufficient range.

Further, in the above embodiment, a case was described in which a part of the light beam LAI is reflected using the half mirror 31 with a reflection efficiency of 1/2, but the present invention is not limited to this, and the half mirror 31 can be used as needed. The reflection efficiency can be freely selected.

Furthermore, in the above-described embodiment, a case has been described in which a part of the light beam LAI sent out through the large-diameter lens 3 is guided to the telescope 5, but the present invention is not limited to this, and the entire light beam LAI is guided to the telescope 5. The collimating scope may be guided to the telescope 5 and removed after the adjustment is completed.

Further, in the above-described embodiment, a case has been described in which the telescope 5 is disposed perpendicularly to the optical axis of the light beam LA1, but the present invention is not limited to this. For example, as shown in FIG. It can also be widely applied when the telescope 5 is placed horizontally with respect to the optical axis of the LAI.

Furthermore, in the above embodiment, a case was described in which the irradiation position of the light beam LAI is detected with the naked eye using the telescope 5, but the observation optical system is not limited to this, and for example, a television camera or the like may be used. good.

Furthermore, in the above-described embodiment, a case has been described in which the present invention is applied to an optical space transmission device configured to transmit information from the transmitting device 30 side to a receiving device, but the present invention is not limited to this. It can also be applied to other optical space transmission devices.

In this case, since the returned light beam can be suppressed, not only can a light beam with less noise be transmitted, but also crosstalk between transmitted and received information can be reduced.

H Effects of the Invention As described above, according to the present invention, the transmitted light beam is reflected within its luminous flux and enters the observation optical system, and after reflecting the incident light beam, it is returned in parallel for observation. By entering the optical system, the returned light beam can be suppressed and an image similar to that obtained when the light source is placed at the irradiation position of the light beam can be obtained. It is possible to detect a position with high accuracy and to transmit information with high quality.

[Brief explanation of the drawing]

FIG. 1 is a route map showing a transmitting device of an optical space transmission device according to an embodiment of the present invention, and FIGS. 2 and 3 are route maps showing conventional transmitting devices. ■, 30... Transmitter, 2... Laser light source, 3... Lens, 5... Telescope,
12.13.21.3 construction...Half mirror-11
5... Corner cube prism. The Emperor's Death (Fig. 1)

Claims (1)

[Scope of Claims] An optical space transmission device configured to transmit the information signal to the receiver via the light beam by sending a light beam modulated with the information signal to the receiver, comprising: a half mirror placed in the flux of the light beam; an observation optical system that receives the reflected light beam of the light beam reflected by the half mirror; , an optical path folding optical system that folds back a reflected light beam of the incident light beam reflected by the half mirror parallel to the optical axis of the reflected light beam, transmits the half mirror, and guides it to the observation optical system. An optical space transmission device characterized by: