JPH10170336A - Device for detecting arriving direction of light - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for detecting arriving direction of light which can shorten the optical axis aligning time by quickly finding the arriving direction of light by widening the scanning extent of each scanning operation. SOLUTION: A device for detecting arriving direction of optical signals arriving at the device through a space is provided with a photodetecting part 10 which detects the optical signals, a slit forming means 11 having a slit which is set so tat the slit can face the part 10 over an elevation set at about 90 deg. or slightly larger, a turning and driving means 12 which turns the means 11, and an arriving direction deciding means 13 which decides the arriving direction of the optical signals based on the output of the section 10 obtained when the means 11 is turned. Therefore, the arriving direction of light can be found by one time of scanning.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical direction-of-arrival detecting device used in an optical space transmission apparatus for transmitting and receiving optical signals through space, and more particularly to an apparatus for quickly positioning an optical axis.

[0002]

2. Description of the Related Art Generally, in order to smoothly transmit and receive information in a limited space such as in an intelligence building, an optical LAN (Local Area Net) is used.
work). In this optical LAN, information is transmitted using light such as infrared light. For example, an optical signal is transmitted between a transmitting / receiving section provided on a ceiling and a transmitting / receiving section as a node at a desk or the like. The transmission / reception unit is provided, and the transmission / reception unit provided on the ceiling is linked to another transmission / reception unit.

As described above, when performing optical communication between two points in space, it is necessary to first align the optical axes of the light emitting element and the light receiving element between the two points. In particular, when invisible light such as infrared light is used for communication, the optical axis adjustment is limited to a relatively narrow allowable range within several tens of degrees. One has to rely on automatic adjustment by a light arrival direction detector equipped with a detector for knowing the arrival direction. 24 and 25 are known as an example of the conventional optical axis alignment.

[0004] Reference numeral 1 denotes a transmitting / receiving unit having a built-in light-emitting element provided on the ceiling, which emits an optical signal 2 in all directions in the space, that is, below the ceiling.
Is detected by the light arrival direction detection device 3 placed on, for example, a desk or the like. The direction of the light arrival direction obtained by the detection device 3 is directed to a photodetector of a transceiver (not shown) attached to the detection device 3.

[0005] The detecting device 3 narrows down the optical signal 2 with a lens or a reflecting mirror and detects it with a photodetector such as a phototransistor or a photodiode. It is output only when the optical signal 2 matches the optical axis. Therefore, the range that can be detected in one scan is very narrow, and the opening angle is 10 degrees or less. For this reason, as shown in FIG.
While rotating by degrees, the angle of the optical axis is changed in the elevation direction for each rotation as shown in FIG. 24, and by repeating this several times, a detection peak point is obtained and transmitted to the transmitting / receiving section 1 on the ceiling. The optical axes are aligned with each other.

[0006]

The reason why the detector 3 must be reciprocated several times in the elevation direction every time the detector 3 is rotated in order to detect the direction of arrival of light is as follows.
That is, the detecting device 3 has a light receiving element for detecting information and detecting the direction of arrival of light near the focal point of one lens or reflecting mirror, and the light receiving range for detecting information is used to reduce disturbance light. The smaller is better, but the wider is better for detecting the direction of arrival of light. Since it is generally not possible to satisfy both requirements with a single lens or a reflecting mirror, the detection range is narrowed here, giving priority to increasing the accuracy of information detection. By increasing the number of scans in space, the object of detecting the direction of arrival of light is achieved. However, in this case, the number of scans on the space increases as described above, and there is a problem that the search time becomes longer.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and is intended to use a light arrival direction detecting device provided separately from an optical system for detecting information to widen a single scanning range. It is an object of the present invention to provide a light arrival direction detecting device capable of quickly finding the light arrival direction and shortening the optical axis alignment time.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an optical direction-of-arrival detecting apparatus for detecting the direction of arrival of an optical signal arriving through space, for detecting the optical signal. A slit forming means having a light detecting portion and a slit set so as to be able to face over an elevation angle of about 90 degrees or slightly larger than the light detecting portion, and the slit forming means. A rotating drive unit configured to rotate, and a light arrival direction determining unit configured to determine an arrival direction of the optical signal based on an output of the light detection unit obtained when the slit forming unit is rotated. It is.

[0009] With this configuration, it is possible to search all the upper hemispherical surfaces by scanning the slit forming means having the slit and the light detecting portion by one rotation in the horizontal direction by the turning drive means. At this time, the light arrival direction determining means determines the direction in which the output value from the light detection unit reaches a peak value during scanning as the light arrival direction.
In this way, it is possible to quickly determine the light arrival direction. If the width of the slit is reduced, the peak value becomes sharper, and the detection accuracy of the light arrival direction can be improved.

In particular, in order to capture an optical signal having an incident angle of within ± 10 degrees, a part or all of the depth from the surface of the slit to the light detecting portion is set to be 5.67 times or more the width of the slit. By setting to, the light capturing angle with respect to the horizontal direction can be set to ± 10 degrees or less, and a steep peak value can be obtained. Further, the slit forming means includes a slit and a light detection unit provided in the light arrival direction, and a slit and a light detection unit provided in another light arrival direction, and the respective light detection units are in directions substantially orthogonal to each other. When the setting is made, by rotating the slit forming means by 180 degrees in the horizontal direction and scanning, all the upper hemispheres can be searched, and the light arrival direction can be determined more quickly. Such a configuration is achieved, for example, by preparing two pairs of slits and photodetectors, and arranging them in the horizontal direction so as to be opposite to each other.

In this case, in particular, the turning drive means is provided not only with a horizontal turning drive but also with a vertical turning drive, and the two pairs of slits and the light detecting section are set at, for example, 90.degree.
If the direction in which the output values of both light detection units are the same value is obtained by turning about 180 degrees, it is possible to accurately determine the position in the height direction of the light arrival direction.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of a light arrival direction detecting apparatus according to the present invention. FIG. 1 is a schematic configuration diagram showing an optical space transmission apparatus having an optical arrival direction detection device of the present invention, FIG. 2 is a front view showing an optical arrival direction detection device of the present invention, and FIG. 3 is a side view of the device shown in FIG. , FIG.
FIG. 5 is a view for explaining the principle of the light arrival direction detection device according to the present invention; FIG. 5 is a diagram showing scanning by the light arrival direction detection device; FIG. 6 is a light detection portion when the light arrival direction detection device is scanned. 5 is a graph showing the output of the above.

As shown in FIG. 1, this optical free space transmission apparatus 4 includes an optical arrival direction detection apparatus 5 provided on the ceiling for determining the direction of the transmission / reception section 1, and an optical signal actually transmitted between the transmission / reception section 1 and the transmission / reception section 1. It has a ground transmitting and receiving unit 6 for performing transmission and reception. The terrestrial transmission / reception unit 6 includes an optical transceiver 7 having a light emitting element and a light receiving element, and a transmission / reception turning drive unit 8 which can turn the transmission / reception device horizontally and vertically. Is directed to the optical axis of the optical transceiver 7 with respect to the light arrival direction obtained by the light arrival direction detection device 5.

For this reason, the terrestrial transmission / reception unit 6 is installed at substantially the same position as the light arrival direction detection device 5, for example, at the same desk. In FIG. 1, the directions from the transmitting / receiving unit 1 to the detecting device 5 and the ground transmitting / receiving unit 6 are different from each other, but actually, the directions are substantially the same. The optical transceiver 7 is connected to one or a plurality of personal computers (not shown) to transmit data. The transmission / reception unit 1 on the ceiling is connected to another similar transmission / reception unit (not shown) so that data can be transmitted to / from another personal computer. doing.

As shown in FIG. 1, the light arrival direction detection device 5 includes a light detection unit 10 for detecting the light signal 2 and a light detection unit 10 having a center at an elevation angle of approximately 90 degrees from the horizontal direction to the vertical direction. Slit forming means 11 for forming slits set so as to be able to face, turning driving means 12 for integrally turning these in the horizontal direction, and an optical signal 2 based on the output value of the photodetector 10. Light arrival direction determination means 13 for determining the arrival direction of
For example, the operation is controlled by a control unit 14 including a microcomputer or the like.

FIGS. 2 and 3 show the structure of the slit forming means 11 and the turning drive means 12 for turning the slit forming means.
The outer surface of the slit forming means 11 is made of, for example, a triangular plastic member or the like. From the oblique side of the triangular member, there is formed a slit groove 14 which is recessed in a triangular shape toward the inside. Therefore, a slit 15 opened in a rectangular shape is formed on the oblique side. Such a slit 15 is not limited to a plastic member, and may be formed by, for example, bending a metal plate or the like.

The light detecting section 10 is provided at the bottom or the back of the slit groove 14 so that the inclination angle α is approximately 45 degrees with respect to the horizontal direction. In this case, when the slit 15 is viewed from the light detection unit 10, the divergence angle in the vertical direction, or the elevation angle in this case, is approximately 90 degrees.
Degrees or slightly more than that. The light detecting unit 10 includes a light detecting element such as a phototransistor or a photodiode, and a light collecting element such as a light collecting lens or light collecting reflector for collecting light. Used. This allows
Optical signal 2 introduced inside through elongated slit 15
Only the light detection unit 10 can detect only the light.

The slit forming means 11 includes
The turning column 16 is mounted on a horizontal turning base 17 provided on the base 6. The base of the turning column 16 is rotatably supported on a base 18 via a bearing 19. Therefore, by rotating the turning column 16, the slit forming means 11 and the light detecting unit 10 can be integrally rotated in a horizontal plane. A circular gear 20 forming a worm wheel is fixed in the middle of the turning support 16, and a worm gear 21 rotatably supported on the base 18 side is meshed with the gear 20. And
The rotation shaft of a horizontal drive motor 22 is directly or indirectly connected to the worm gear 21 via a speed reducer or the like so that the worm gear 21 can rotate.

Next, the operation of the apparatus of the present invention configured as described above will be described. An optical signal 9 from the light source (light emitting element) of the transmitting / receiving unit 1 shown in FIG.
Has been released. In this state, by driving the horizontal drive motor 22, the turning column 16 is turned, and the slit forming means 11 in which the light detection unit 10 is housed at the back is rotated once over a horizontal plane. The output value from the unit 10 is stored in the light arrival direction determining means 13, and the light arrival direction is determined based on the output value.

At this time, the light detecting section 10 detects only the optical signal introduced into the inside through the elongated slit 15, and the angle at which the light detecting section 10 can face the outside through the slit is substantially the same. Since it is set to 90 degrees or slightly larger than it by about several degrees, by rotating this one time in the horizontal plane, the direction in which the output value from the light detection unit 10 reaches a peak is the light arrival direction. Can be recognized.

The above points will be described with reference to FIGS. FIG. 4 schematically shows the slit forming means 11 and the light detection unit 10 shown in FIGS. By the slit forming means 11, a predetermined width W and a predetermined length L
Is formed, and the light detection unit 10 is disposed behind the slit 15. That is, both sides of the light detection unit 10 are shielded from the outside by right-angle walls. The light detection unit 10 has its optical axis directed at a direction of 45 degrees with respect to the horizontal direction, and the opening angle with respect to the slit 15 is set to approximately 90 degrees.

Here, the slit forming means 11 is rotated one turn clockwise around the rotating shaft 23 in FIG. FIG. 5 is a view of the state as viewed from directly above. The output of the light detection unit 10 when the light source as the transmission / reception unit 1 provided on the ceiling is placed at a position of, for example, 270 degrees is as shown in FIG. That is, the peak of the output value comes at a position of 270 degrees. When the rotation is stopped at the angle of the peak value, the slit 15 faces the light source 1. That is, the direction in which this peak value is obtained is the light arrival direction.

In this case, if the height of the light source 1 is too high or too low, a sufficient output may not be obtained.
As shown in FIG. 7, the light source 1 is moved from 0 degree to 9 degrees with respect to the horizontal direction.
When the level shift of the peak value is examined by moving over the range of 0 degrees, the result shown in FIG. 8 is obtained, and no problem occurs. That is, as is clear from FIG. 8, the peak value level is a value at which the height of the light source 1 decreases to some extent near 0 ° and 90 °, but the peak value can be sufficiently detected. That is, even if the height of the light source 1 is within a wide range from 10 degrees to 90 degrees, it can be detected. Therefore, no matter where the light source 1 is located on the hemispherical surface of the space, the light arrival direction can be detected only by rotating the light detection unit 10 once in the horizontal plane. In FIG. 8, even when the height of the light source is 0 degree or 90 degrees, a slight output is obtained from the light detection unit.

By the way, in order to detect the direction of the light source 1 with higher accuracy, it is possible to reduce the influence of disturbance light by taking in light in a narrow range. It is necessary to determine the direction. Next, the relationship between the width W and the depth D of the slit 15, that is, the distance to the light detection unit 10 will be examined. In FIG. 9, the slit 1
The width of 5 (light detection unit) is W, the depth (distance to the light detection unit 10) is D, and the incident angle of the parallel optical signal 9 is θ. Although the length of the slit 15 is related to the absolute amount of the output, it does not affect the waveform of the output with respect to the incident angle θ, and is excluded from the calculation. If the width of the light signal 9 hitting the light detection unit 10 is W (θ), the following equation 1 holds.

W (θ) = WDtan (θ) (1) When the incident angle θ is 0 degree, that is, when the light source 1 comes directly above,
Since tan (θ) is zero, W (0) = W. If the output is normalized with this value to be F (θ), the following equation 2 is obtained. F (θ) = W (θ) / W = 1− (D / W) · tan (θ) (2)

Equation 2 is represented in FIG.
When (θ) = 0, tan (θ) = W / D (Equation 3). Here, in order to capture light having an opening angle of ± 10 degrees (incident angle θ), the relationship between W and D is derived by calculating Equation 3 with θ = 10. In this case, D / W = 5.67
And the depth D is 5.67 with respect to the width W of the slit 15.
It becomes clear that if it is twice or more, the take-in angle is within ± 10 degrees. As a result, the light arrival direction can be determined with high accuracy.

Next, the light take-up angle (elevation angle) in the height direction (up-down direction) with respect to the light detection unit 10 will be examined.
FIG. 11 is a diagram for explaining the relationship between the incident angle θ1 of light and the output of the light detection unit when there is nothing blocking light around the light detection unit 10. However, it is assumed that there is no light reflection on the surface of the light detection unit 10. At this time, if the output of the light detection unit 10 is W (θ1), the following equation 4 is obtained. W (θ1) = W · COS (θ1) (4) where W is the width of the light detection unit 10.

Here, when the incident angle θ1 = 0, W (0) = W
(Equation 5), which is normalized to give the following Equation 6. F (θ1) = W (θ1) / W = COS (θ1) (6) From Equation 6, θ1 which is 70% of the maximum value is 45.57 degrees. That is, if it is within ± 45 degrees (the opening angle is 90 degrees), a sufficient output of 70% or more of the peak value can be secured. Accordingly, by setting the light taking-in angle (elevation angle) in the height direction of the slit forming means 11 to around 90 degrees, the change in the output level is relatively less than 30% of the peak value, and the space of the hemisphere is reduced by one. It turns out that this is the minimum angle necessary for scanning by rotation. In the above embodiment, the case where a pair of the slit 15 and the light detection unit 10 is used is shown. However, the present invention is not limited to this, and a plurality of pairs may be provided at equal intervals in the circumferential direction. For example, slit 1
5 and two light detection units 10 can be combined to enhance the ability to detect the direction of arrival of light.

Next, an example will be described with reference to the drawings. FIG. 12 is a front view showing a second embodiment of the device of the present invention,
FIG. 13 is a side view of the apparatus shown in FIG. 12, and FIG. 14 is a perspective view showing a main part of the second embodiment. Here, the slit forming means includes a slit 15 and a light detection unit 10 provided in the light arrival direction, and a slit 15A and a light detection unit 10A provided in another light arrival direction.
0A is a direction that is substantially orthogonal. Specifically, with respect to the slit 15 and the light detection unit 10, the slit 15A and the light detection unit 10
A is arranged. That is. The slits 15 and 15A are made to face in opposite directions by making the slits different from each other by 180 degrees by the slit forming means 11, and the photodetectors 10 and 10A are provided behind them (FIG. 1).
4). The two are fixed so as not to move relatively.

The slit forming means 11 is not directly mounted and fixed on the horizontal rotating base 17 as shown in FIG. 2, but is used as the vertical rotating base 2 as shown in FIGS.
5 and is fixed. At both ends of the base 25, support shafts 26, 26 are provided.
6 is rotatably supported by bearings 27, 27 on two columns 24, 24 erected from the horizontal rotating base 17. A ring-shaped vertical gear 2 forming a worm wheel is provided on one of the support shafts 26, 26.
8 is fixed to the vertical gear 28, and the vertical worm gear 2, which is fixedly supported on the horizontal rotating base 17 side, is attached to the vertical gear 28.
9 are meshed. And this vertical worm gear 2
A rotation shaft of a vertical drive motor 30 is connected to 9 directly or indirectly via a speed reducer or the like, so that the vertical worm gear 29 can be rotated. This allows
The vertical turning drive 32 is formed. Therefore,
By rotating the worm gear 29, the vertical rotation base 25 can be rotated or rocked vertically in a vertical plane. Thereby, the light detection unit 10,
10A is adapted to be rotatable in horizontal and vertical planes. Note that other configurations and functions thereof are the same as those described above, and thus, the same reference numerals are given here, and description thereof will be omitted.

Next, the operation of the second embodiment will be described. FIG. 15 is a schematic diagram showing the arrangement relationship between the slits and the photodetectors of the second embodiment, FIG. 16 is a diagram showing a scan in a horizontal plane of the second embodiment, and FIG. 17 is a diagram showing a scan in a horizontal plane of the second embodiment. FIG. 18 is a graph showing the output of the light detection unit when the height of the light source is changed within the hemisphere, and FIG. 19 is a graph showing the state of the light source when the height of the light source is changed within the sphere. FIG. 20 is a graph showing an output of the light detection unit, and FIG. 20 is a graph showing an output of the light detection unit when the light detection unit is scanned in a vertical plane when the light source is positioned in the height direction of 30 degrees.

In FIG. 16, the center of rotation 31 in the horizontal plane is shown.
Is the center between the photodetectors 10 and 10A, and the light source (transmitter / receiver) 1 is placed at a position of 105 degrees. First, the photodetector 10 is set at a position of 0 degrees, and 180
Rotate to a degree. The outputs of the photodetectors 10, 10A at that time are represented as shown in FIG. That is. There is an output peak at a position of 105 degrees on the light detection unit 10 side. On the other hand, no output is output to the other light detection unit 10A. Next, at the position of the peak of the output on the light detection unit 10 side,
The light detection units 10 and 10A are rotated in the height direction, that is, in the vertical plane. The rotation or rotation of the light detection units 10 and 10A in the height direction is performed by the vertical drive motor 30 of the vertical rotation drive unit 32.
To rotate the vertical rotation base 25 in the height direction.

In FIG. 18, the height of the light source is changed in place of the light detecting section, and the light source 1 is moved 180 degrees in a semicircular shape in the height direction as shown by an arrow 33. The output at this time is represented as shown in FIG.
, And the output from the other photodetector 10A is obtained immediately before the angle of 90 degrees. The light source 1 is a two-light detector 1
0, 10A, that is, in this case, when located in the direction of 90 degrees in the height direction, the two light detection units 1
Although the outputs of 0 and 10A are decreasing, they are the same. That is, when the light source 1 is positioned in the extension direction of the line symmetry axis of the light detection units 10, 10A, the light detection units 10, 10A
The output of A is substantially the same.

Now, in such a situation, it is assumed that the light source 1 is located at a height of 30 degrees in FIG. When the two light detection units 10 and 10A are rotated 90 degrees in a counterclockwise direction (the direction opposite to the arrow 33),
An output as shown in FIG. 20 can be obtained. That is, the light detection units 10 and 10A are moved from the state shown in FIG.
When rotated by one degree, the outputs of the two light detection units 10 and 10A become the same, and the height direction, that is, the elevation angle is 30 degrees (= 90 degrees).
The light source 1 is located in the height direction of (−60 degrees), and it can be recognized that this is the light arrival direction.

That is, in the horizontal direction, the direction of the light arrival direction in the horizontal plane can be known only by rotating by 180 degrees as shown in FIG.
The direction can be determined more quickly than when a degree of rotation is required. Furthermore, in a state where one of the light detection units is oriented in the light arrival direction, by rotating this in the height direction, the elevation angle of the light arrival direction can also be detected, as compared with the previous embodiment. It is possible to specify the position of the light source not only in the horizontal direction but also in the height direction. In the second embodiment, if the opening angle of the slit with respect to the height direction from the light detection unit is set slightly larger than 90 degrees, for example, about several degrees, the two light detection units 1 in FIG.
The crossing level of the outputs of 0 and 10A can be made higher by that amount, and the same level detection operation can be easily performed.

Further, in this embodiment, the front shape of the slit forming means 11 with respect to one light detecting section 10 is triangular as shown in FIGS. 2 and 12, but the slit shape greatly changes to the slit shape facing the light detecting section. , Any shape may be used, for example, a square shape as shown in FIG. 21 or a fan shape as shown in FIG.
FIG. 23 shows the external shape of the second embodiment when it is square as shown in FIG. Further, the mechanism for rotating and driving the light detection unit in a horizontal plane or a vertical plane is merely an example here, and is not limited to the worm gear and the gear, but uses another drive mechanism, for example, a belt and a pulley. You may do so.

[0037]

As described above, according to the light arrival direction detecting device of the present invention, the following excellent operational effects can be exhibited. By turning the light detection unit that detects the light signal introduced through the slit in a horizontal plane, the light arrival direction at which the light signal arrives can be quickly obtained, and therefore, the time required for optical axis alignment is reduced. be able to. By arranging the light detection unit and the slits two-to-back, the direction of arrival of light can be obtained even when the turning angle in the horizontal plane is half, and the direction determination operation can be performed promptly accordingly. Further, in this case, the light arrival direction can be recognized not only in the horizontal direction but also in the height direction by two rotation operations in the horizontal direction and the height direction, and the detection accuracy can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an optical space transmission device having an optical arrival direction detection device of the present invention.

FIG. 2 is a front view showing a light arrival direction detection device of the present invention.

FIG. 3 is a side view of the device shown in FIG. 2;

FIG. 4 is a principle explanatory diagram for explaining the principle of the light arrival direction detecting device of the present invention.

FIG. 5 is a diagram illustrating scanning by the light arrival direction detection device.

FIG. 6 is a graph showing an output of the light detection unit when scanning the light arrival direction detection device.

FIG. 7 is a diagram showing a state when the light source changes in the height direction.

FIG. 8 is a graph showing the output of the light detection unit when the light source changes in the height direction.

FIG. 9 is a diagram illustrating a relationship between an incident angle and a distance between a slit and a light detection unit.

FIG. 10 is a graph showing the output of the light detection unit with respect to the incident angle θ in the horizontal direction.

FIG. 11 is a diagram showing the relationship between the incident angle θ1 in the height direction and the output of the light detection unit.

FIG. 12 is a front view showing a second embodiment of the device of the present invention.

FIG. 13 is a side view of the device shown in FIG.

FIG. 14 is a perspective view showing a main part of the second embodiment.

FIG. 15 is a schematic diagram illustrating an arrangement relationship between a slit and a light detection unit according to a second embodiment.

FIG. 16 is a diagram illustrating scanning in a horizontal plane according to the second embodiment.

FIG. 17 is a graph showing the output of the light detection unit when scanning in a horizontal plane according to the second embodiment.

FIG. 18 is a diagram showing a state when the height of a light source is changed within a hemisphere.

FIG. 19 is a graph showing the output of the light detection unit when the height of the light source is changed within the spherical surface.

FIG. 20 is a graph illustrating an output of the light detection unit when the light detection unit is scanned in a vertical plane when the light source is positioned in a height direction of 30 degrees.

FIG. 21 is a view showing a modification of the shape of the slit forming means.

FIG. 22 is a view showing another modification of the shape of the slit forming means.

23 is a perspective view when two pairs of slit forming means shown in FIG. 21 are provided.

FIG. 24 is a diagram illustrating a general relationship between a transmission / reception unit (light source) and a light arrival direction detection device.

25 is a diagram showing a scanning method of the detection device shown in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Transmission / reception part (light source), 2 ... Optical signal, 5 ... Light arrival direction detection apparatus, 6 ... Ground transmission / reception part, 10 ... Light detection part, 11 ... Slit forming means, 12 ... Turning drive means, 13 ... Light arrival direction Determination means, 15: slit, 17: horizontal turning base, 2
5: Vertical turning base, 32: Vertical turning drive.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI H04B 10/10 10/22 (72) Inventor Takera Sasura 3-12 Moriyacho, Kanagawa-ku, Yokohama, Kanagawa Prefecture Victor Company of Japan, Ltd. (72) Inventor Kenji Narusawa 3-12-12 Moriyacho, Kanagawa-ku, Yokohama-shi, Kanagawa Prefecture Inside (72) Inventor Junichi Kubota 3-12-12 Moriyacho, Kanagawa-ku, Yokohama-shi, Kanagawa Japan Victor Company of Japan Inside

Claims (5)

[Claims] 1. A light arrival direction detecting device for detecting an arrival direction of an optical signal arriving in a space, comprising: a light detection unit for detecting the light signal; and approximately 90 degrees around the light detection unit. A slit forming means having a slit set so as to be able to face over a slightly larger elevation angle; a turning drive means for turning the slit forming means; and a turning drive means for turning the slit forming means. A light arrival direction determining unit that determines the direction of arrival of the optical signal based on the output of the light detection unit. 2. A part or all of the depth from the surface of the slit to the light detecting portion is 5.67 times or more the width of the slit in order to capture an optical signal within an incident angle of ± 10 degrees. The length is set to a length.
The light arrival direction detection device according to any one of the preceding claims. 3. The slit forming means includes a slit and a light detection unit provided in a light arrival direction, and a slit and a light detection unit provided in another light arrival direction, and the respective light detection units are substantially orthogonal to each other. The light arrival direction detecting device according to claim 1, wherein the direction is a direction. 4. The light arrival direction detecting device according to claim 1, wherein the turning drive unit includes a horizontal turning drive unit that drives the slit forming unit to turn in a horizontal plane. 5. The turning drive unit includes a horizontal turning drive unit that drives the slit forming unit to turn in a horizontal plane, and a vertical turning drive unit that drives the slit forming unit to turn in a vertical plane. The light arrival direction detecting device according to claim 3, wherein