JP2785193B2 - Transmission device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a transmission device, and is suitably applied, for example, to an optical space transmission device that performs bidirectional optical space transmission.

B. Summary of the Invention In the present invention, a transmitting device separates a light beam to be transmitted to a transmission target and a light beam to be applied to an observation optical system by a filter optical system having wavelength selectivity, so that light can be more easily compared with the conventional one. The irradiation position of the beam can be adjusted.

C Prior Art Conventionally, in this type of optical space transmission device, there has been proposed an optical space transmission device capable of easily detecting an irradiation position of a light beam on a transmission side (Japanese Patent Application No. 63-123543, Japanese Patent Application No. 63-123543; Noriaki 63
-134230).

That is, in FIG. 2, reference numeral 1 denotes an optical space transmission device as a whole, and a laser light source 2 for emitting a light beam LA1 modulated by a predetermined information signal is arranged in a housing 1A.

A large-diameter lens 3 is arranged on the front surface of the laser light source 2 so that the light beam LA1 emitted from the laser light source 2 is converted into a parallel light beam and transmitted to a transmission target.

On the other hand, a collimator scope 4 is provided on the front surface of the lens 3 so that the irradiation position of the light beam LA1 can be detected.

That is, the collimating scope 4 reflects the light beam LA1 at an angle of approximately 90 degrees with the half mirror 5,
A part of the light beam LA1 is separated, and the resulting reflected light beam LA2 is guided to the corner cube prim 6.

Accordingly, the reflected light beam L whose optical axis is turned back in parallel to the reflected light beam LA2 through the corner tube prism 6
A3 is obtained, and the reflected light beam LA3 is guided to the telescope 7.

Thus, in the telescope 7, the reflected light beam LA3
, The image of the laser light source 2 can be observed.

Further, in the collimator scope 4, light (hereinafter referred to as observation light) LA 4 arriving from the transmission target side is reflected by the half mirror 5 and guided to the telescope 7 so that the transmission target side can be observed in addition to the image of the light source 2. Has been made.

Accordingly, by reflecting the light beam LA1 by the half mirror 5 and then turning the optical axis in parallel, in the observation light LA4, the component whose optical axis is parallel to the light beam LA1 becomes parallel to the reflected light beam LA3. The light enters the telescope 7.

As a result, a reflected light beam LA3 emitted from the irradiation position of the light beam LA1 can be obtained, so that an image in which the light source 2 is arranged at the irradiation position of the light beam LA1 can be observed.

Therefore, the irradiation position of the light beam LA1 can be easily detected on the optical space transmission device 1 only by capturing the transmission target within the field of view of the telescope 7, thereby simplifying the installation work of the optical space transmission device. It has been made possible.

D. Problems to be Solved by the Invention In the configuration of FIG. 2, when the telescope 7 observes the transmission target, the amount of the observation light LA4 is insufficient compared with the reflected light beam LA3, and the irradiation of the light beam LA1 is performed. There were still practically insufficient problems to adjust the position.

One method for solving this problem is to increase the reflectivity of the half mirror 5 and increase the amount of observation light LA4 reflected by the half mirror 5.

However, when the reflectance of the half mirror 5 is increased,
Accordingly, the light amount of the light beam LA1 transmitted through the half mirror 5 decreases and the light amount of the reflected light beam LA3 increases.

In this case, when the light amount of the light beam LA1 transmitted through the half mirror 5 decreases, it becomes difficult to detect the light beam LA1 in the transmission target and finely adjust the irradiation position of the light beam LA1.

Further, when the light amount of the reflected light beam LA3 is increased, the light amount of the light beam LA1 returned to the laser light source 2 is increased.
It becomes difficult to transmit information with high quality.

The present invention has been made in view of the above points, and it is an object of the present invention to propose an optical space transmission device that can easily adjust the irradiation position of the light beam LA1 as compared with the related art.

E. Means for Solving the Problem In order to solve such a problem, in the present invention, a light beam LA1 modulated based on an information signal is supplied to a predetermined light source 2
In the transmitting apparatus 1 that spatially transmits the information signal to the transmission target via the light beam LA1 by transmitting the light beam LA1 to the transmission target by spatially transmitting the light beam LA1, the light beam emitted from the light source 2 A filter optical system 11 having a wavelength selectivity that transmits most of LA1 toward the transmission target and reflects a part LA2 of the light beam LA1 and reflects most of the observation light LA4 coming from the transmission target.
And a part L of the light beam LA1 reflected by the filter optical system 11.
The observation light LA4 reflected by the filter optical system 11 by folding the A2 and transmitting the light through the filter optical system 11 is reflected.
An optical path turning optical system 6 for converting the light beam LA1 into a combined light beam, an image of the light source 2 indicating an irradiation position of the light beam LA1 obtained based on a part LA3 of the light beam LA1 by the incidence of the combined light beam, and the observation light LA4. And an observation optical system 7 for superimposing and observing an image to be transmitted obtained based on the above.

F function Most of the light beam LA1 emitted from the light source 2 is transmitted toward the transmission target, and part of the light beam LA1 is reflected, and most of the observation light LA4 arriving from the transmission target is reflected. Filter optical system with selective wavelength
11 and an observation light reflected by the filter optical system 11 by transmitting a part of the light beam LA1 reflected by the filter optical system 11 and returning the laser beam to the filter optical system 11.
An optical path turning optical system 6 for forming a combined light beam with LA4, an image of the light source 2 indicating an irradiation position of the light beam LA1 obtained based on a part LA3 of the light beam LA1 when the combined light beam is incident, and observation light By providing the observation optical system 7 for superimposing and observing the image of the transmission target obtained based on LA4, the observation optical system 7 can be provided while preventing the light amount of the light beam LA1 transmitted to the transmission target from decreasing. By increasing the amount of the observation light LA4 to be incident, the irradiation position of the light beam LA1 on the transmission target can be more easily and accurately detected than before.

Further, since the light amount of the light beam LA1 to be transmitted to the transmission target is prevented from decreasing, the light beam
The light amount of LA1 can be greatly reduced.

G Examples Hereinafter, examples of the present invention will be described in detail with reference to the drawings.

In FIG. 1, in which parts corresponding to those in FIG. 2 are denoted by the same reference numerals, reference numeral 10 denotes a bidirectional optical space transmission device as a whole, wherein a dichroic mirror 11 is used in place of the half mirror 5 and a transmission object is transmitted. And a light beam LA2 to be incident on the telescope 7 are separated.

That is, the dichroic mirror 11 has wavelength selectivity. In this embodiment, the dichroic mirror 11 selectively (almost) emits the light beam LA1 having a wavelength of 800 to 1300 [nm] emitted from the laser light source 2.
While transmitting with a transmittance close to 100%, a visible light ray (that is, a wavelength of 400 to 700 [n
m]) is selectively reflected (with a transmittance close to 100%).

Accordingly, it is possible to prevent a decrease in the light amount of the light beam LA1 to be transmitted to the transmission object and increase the light amount of the observation light LA4 incident on the telescope 7, thereby making it possible to increase the irradiation position of the light beam LA1 as compared with the conventional case. Thus, the detection can be further simplified.

At this time, assuming that the reflectance of the dichroic mirror 11 with respect to the light beam LA1 is R, the conical tube prism 6
After being reflected by the dichroic mirror 11, the amount of the reflected light beam LA3 that passes through the dichroic mirror 11 and enters the telescope 7 is expressed by the following equation with respect to the light beam LA1. By selecting the reflectance R, the brightness of the image of the laser light source 2 observed through the telescope 7 can be set to a desired brightness with respect to the brightness of the scene to be transmitted. .

Therefore, not only can the scene of the transmission target observable by the telescope 7 be brightened, but also the image of the laser light source 2 can be set to a brightness corresponding to the brightness of the scenery, thereby making the light beam more easily. The irradiation position of LA1 can be detected.

On the other hand, the amount of light of the reflected light beam LA5 reflected by the dichroic mirror 11 is expressed by the following equation with respect to the light beam LA1. As a result, the light amount of the light beam LA1 returned to the laser light source 2 can be significantly reduced as compared with the related art.

Thus, in this embodiment, the dichroic mirror
11 is a light beam LA1 transmitted from the lens 3 to the transmission target.
Constitutes a filter optical system having a wavelength selectivity that transmits most of the light and partially reflects the light, and reflects the observation light LA4 arriving from the transmission object. Light beam LA reflected by the system
2 constitutes an optical path turning optical system for turning back the optical beam LA2 in parallel with the optical axis of the light beam LA2. An observation optical system for observing the observation light LA4 reflected by the system is configured.

According to the above configuration, the light beam LA1 to be transmitted to the transmission object is separated from the light beam LA2 to be incident on the telescope 7 by the dichroic mirror 11, so that the light amount of the light beam LA1 to be transmitted to the transmission object is increased and the light source The light amount of the light beam LA1 returned to the telescope 7 can be reduced, and the light amount of the observation light incident on the telescope 7 can be increased.

As a result, it is possible to obtain an optical space transmission device that can more easily detect the irradiation position of the light beam LA1 as compared with the related art.

Note that, in the above-described embodiment, the wavelength
Although the case where the light beam LA1 of 800 to 1300 [nm] is emitted has been described, the present invention is not limited to this, and the laser light source 2 may emit a light beam of, for example, visible light. A dichroic mirror that selectively transmits light with respect to the wavelength of the light beam emitted from the light source 2 may be used.

Further, in the above-described embodiment, the case where the telescope is used as the observation optical system has been described. However, the observation optical system is not limited to this, and an imaging device such as a television camera may be used.

Further, in the above-described embodiment, the case where the light beam LA1 is transmitted using the laser light source is described. However, the present invention is not limited to this, and can be widely applied to a case where a light source such as a light emitting diode is used. .

Further, in the above-described embodiment, the case where the present invention is applied to the two-way optical space transmission device has been described. However, the present invention is not limited to the two-way optical space transmission device, but is widely applied to various optical space transmission devices. can do.

H Effects of the Invention As described above, according to the present invention, most of the light beam emitted from the light source is transmitted toward the transmission target, and a part of the light beam is reflected, and the light beam coming from the transmission target is transmitted. A filter optical system having wavelength selectivity that reflects most of the observation light, and a part of the light beam reflected by the filter optical system is turned back and transmitted through the filter optical system to be reflected by the filter optical system. An optical path turning optical system that combines the observation light with the observation light, an image of a light source indicating an irradiation position of the light beam obtained based on a part of the light beam when the combined light is incident, and the observation light. By providing an observation optical system that superimposes the obtained image of the transmission target on the observation optical system, the observation light that enters the observation optical system while preventing the light amount of the light beam transmitted to the transmission target from decreasing is prevented. And the light beam irradiation position on the transmission target can be detected more easily and more accurately than before, and thus the light beam irradiation position on the transmission target is simpler than before. It is possible to realize a transmission device that can be adjusted to the above.

Further, since the light amount of the light beam to be transmitted to the transmission target is prevented from being reduced, the light amount of the light beam returned to the light source can be significantly reduced.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a free-space optical transmission apparatus according to one embodiment of the present invention, and FIG. 2 is a schematic diagram showing a conventional free-space optical transmission apparatus. 1, 10 ... optical space transmission device, 2 ... laser light source, 3 ...
Lens, 6 ... Corner cube prism, 11 ... Dichroic mirror.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H04B 10/10 H04B 10/22-10/24

Claims (1)

(57) [Claims] A light beam modulated based on an information signal is emitted from a predetermined light source, and the light beam is transmitted spatially and transmitted to a transmission target, whereby the information signal is transmitted via the light beam. In the transmitting apparatus for transmitting the optical space to the transmission target, most of the light beam emitted from the light source is transmitted toward the transmission target, and a part of the light beam is reflected, and the light beam coming from the transmission target is reflected. A filter optical system having a wavelength selectivity for reflecting most of the observation light to be reflected, and the filter optical system by transmitting a part of the light beam reflected by the filter optical system to the filter optical system by folding the part. An optical path turning optical system for forming a combined light beam with the observation light reflected by the light beam, and obtaining the combined light beam based on the part of the light beam by making the combined light beam incident. An image of the light source that indicates the irradiation position of the light beam, transmitting apparatus characterized by comprising an observation optical system for observing overlapping and the transmission of the target image obtained based on the observed light.