JPH06259696A - Information transmission system - Google Patents

Abstract

PURPOSE:To provide the information transmission system which can reduce the state of disabling the transmission of information, can reduce the erroneous recognition of information, can be utilized for any large scale system as well and further can increase the quantity of information. CONSTITUTION:An information transmitter 30 successively sends the plural kinds of information to corner cubes 11. A beam light transmitter/receiver 21 scans the corner cubes 11 by turning a planar laser beam LB. Since the width of this laser beam LB is wide in a scan direction and a vertical direction, the small corner cubes 11 can be easily irradiated with the laser beam LB even when an optical axis center S is deviated a little. Thus, the beam light returns from the corner cubes 11 to the beam light transmitter/receiver 21 without fail. On the other hand, since the entire faces of corner cubes 11a-11c are scanned, the reflected light to return to the beam light transmitter/receiver 21 contains all the information. Further, since the reflected light successively contains the plural kinds of information, the quantity of information is considerably increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information transmission system, and more specifically, it is used in a position detection system, a traffic control system, a navigation system, etc., and transmits information from a corner cube by using a light beam. Regarding things.

[0002]

2. Description of the Related Art FIG. 19 is a diagram showing the entire structure of a position detecting system for a moving body in which a conventional information transmission system is used, which is disclosed in Japanese Patent Publication No. 4-52658.
A plurality of (three in the figure) corner cubes 111a are provided at predetermined positions on the side of the road on which the automobile 101 runs.
~ 111c are arranged. A beam light transmitting / receiving device 121 is mounted on the automobile 101. The beam light transmission / reception device 121 emits beam light having a sharp directivity, such as a laser beam LB ′, while rotating. By rotating the laser beam LB 'in this manner, a wide range can be linearly scanned. Each of the corner cubes 111a to 111c returns the incident light to the same angle as the incident angle and parallel to the incident light regardless of the incident angle. Therefore, the laser beam LB ′ emitted from the beam light transmitter / receiver 121 is supplied to the corner cube 111.
If any of a to 111c is hit, the laser beam L
B'is reflected and returns to the beam light transmitting / receiving device 121. The laser beam LB ′ returned to the beam light transmitting / receiving device 121 is incident on a single light receiving element provided in the beam light transmitting / receiving device 121. This light receiving element outputs a detection signal corresponding to the reflected light.

FIG. 20 is a front view showing a corner cube 111 provided with a mask, and FIG. 21 is a view showing a detection signal of a light receiving element. Each corner cube 111a-1
Reference numeral 11c has three light reflecting mirror surfaces 112, 113, 114 which are arranged in a triangular pyramid shape while maintaining an angle of 90 degrees with each other. Each corner cube 111a-111c
Are attached with masks 131, 132, and 133 representing information, respectively.

The light reflecting mirror surface 1 of the corner cube 111a
A fan-shaped mask 131 is fixedly provided on a part of 12 to represent information of the corner cube 111a itself (see FIG. 20 (1)). Such a mask 131 is formed, for example, by applying a paint. Mask 1
The above-mentioned reflection condition is maintained in the portion not marked with 31, but the light incident on the mask 131 is not reflected because it is absorbed by the mask 131 and interferes with the reflection condition. Here, the light reflected by the light reflecting mirror surface 113 may pass through the mask 131 of the light reflecting mirror surface 112 after being reflected by the light reflecting mirror surface 114 or directly. Also in this case, the reflection condition is obstructed, so that no reflection occurs. That is, by disposing the mask 131 on the light reflecting mirror surface 112, the light reflecting mirror surface 112 can be extended to a virtual surface extending from the intersection O of the light reflecting mirror surfaces 112 to 114.
This is equivalent to disposing one virtual mask 131a, 131b, 131c. Therefore, the masks 131 and 13
1a, 131b, 131c are arranged in a circle centered on the intersection O.

It is assumed that the laser beam LB 'emitted from the beam light transmitting / receiving device 121 hits the corner cube 111a, and this laser beam LB' linearly scans the portions α1, α2, α3 of the corner cube 111a (FIG. 20). reference). In this case, the laser beam L
B'is reflected at the portions α1 and α3 of the corner cube 111a, but is masked at the portion α2.
The reflection is blocked by 1,131a. Therefore, the light receiving element outputs the detection signal shown in FIG. 21A by observing the portions α1, α2, and α3 for each pixel. The pulses p1 and p2 included in this detection signal are the corner cube 111.
This is due to the reflection of the laser beam LB ′ at the portions α1 and α3 of a. The low level portion sandwiched between the pulses p1 and p2 is due to the obstruction of the reflection of the laser beam LB ′ at the portion α2 of the corner cube 111. Therefore, since the detection signal output from the light receiving element is digitally modulated by the masks 131 and 131a,
The detection signal contains part of the information.

The light reflecting mirror surface 1 of the corner cube 102b
12 represents the information of the corner cube 111b itself, the ridge line L between the light reflecting mirror surface 112 and the light reflecting mirror surface 114.
Two short rod-shaped masks 132 perpendicular to 1 are fixedly arranged (see FIG. 20 (2)). In this case, this is equivalent to disposing three virtual masks 132a, 132b, 132c. Therefore, the masks 132, 132
a, 132b, 132c are arranged in four bar codes along the ridge line L1.

When the laser beam LB 'emitted from the beam light transmitting / receiving device 121 linearly scans the portions β1 to β9 of the corner cube 111b, for example, the laser beam L
B'is the part β1, β3, β of the corner cube 111b
It is reflected at 5, β7 and β9. However, the part β
2, β4, β6, β8, masks 132, 132
The reflection is blocked by a and 132b. Therefore, the light receiving element is shown in FIG.
The detection signal shown in (2) is output. The pulses p1 to p5 included in this detection signal are due to the reflection of the laser beam LB ′ at the portions β1, β3, β5, β7, β9 of the corner cube 111b. The low level portions sandwiched between the pulses p1 to p5 are due to the inhibition of the reflection of the laser beam LB 'at the portions β2, β4, β6, β8 of the corner cube 111b. Therefore, the detection signal output from the light receiving element is the mask 13
Since it is digitally modulated by 2, 132a and 132b, a part of information is included in the detection signal.

Light reflecting mirror surface 1 of the corner cube 111c
12 represents the information of the corner cube 111c itself, and therefore, the light reflecting mirror surface 112 and the light reflecting mirror surface 11 from the ridge line L1.
Three rod-shaped masks 133 that are tangential to a circle centered on the intersection point O and extend to the ridge line L2 with respect to 3 are fixedly arranged (see FIG. 20 (3)). In this case, it is equivalent to disposing three virtual masks 133a, 133b, 133c. Therefore, these masks 133, 133a,
133b and 133c are arranged in three hollow rectangles centering on the intersection O.

When the laser beam LB 'emitted from the beam light transmitting / receiving device 121 linearly scans the portions γ1 to γ13 of the corner cube 111c, the laser beam LB' is the portions γ1, γ3 of the corner cube 111c.
It is reflected at γ5, γ7, γ9, γ11, and γ13. However, the parts γ2, γ4, γ6, γ8, γ10, γ
At 12, the reflection is blocked by the masks 133 and 133b. For this reason, the light receiving element has portions γ1 to γ13.
For each pixel to output the detection signal shown in FIG. The pulses p1 to p7 included in this detection signal are the portions γ1, γ3, γ5, γ of the corner cube 111c.
Laser beam LB ′ at 7, γ9, γ11, γ13
It is due to the reflection of. The low level portions sandwiched between the pulses p1 to p7 are the corner cubes 11
This is due to the inhibition of the reflection of the laser beam LB ′ in the portions γ2, γ4, γ6, γ8, γ10, γ12 of 1c. Therefore, since the detection signal output from the light receiving element is digitally modulated by the masks 133 and 133b,
The detection signal contains part of the information.

The detection signal of the light receiving element is given to a counter, for example, and the number of pulses is counted. The count output of the counter is given to the judging device. The determination device analyzes the information transmitted from the corner cube 111 based on the count output of the counter. The determination device is a mask 131, 13
Information of 2, 133 is stored in advance. Therefore, the judging device judges from which corner cube the reflected light is received by comparing the count value of the counter with the information stored in advance. It is also disclosed that the information of the corner cube 111 can be recognized by the pulse width of the pulse of the digitally modulated detection signal output from the light receiving element.

[0011]

However, in the conventional information transmission system, since the corner cube is scanned by the beam light having a sharp directional spot,
Beam light into small corner cubes (eg 1 cm to a few
cm) is very difficult to apply. In particular, when the vehicle is tilted to the left or right due to the unevenness of the road surface, the scanned beam light is significantly deviated from the corner cube. In this case, the light beam does not return from the corner cube. Therefore, there has been a problem that the state in which the information cannot be transmitted from the corner cube frequently occurs.

Further, since the corner cube is scanned with the light beam having a sharp directivity, even if the light beam can be applied to the corner cube, the corner cube can only be scanned with the line light beam. Can not do it. Therefore, the digitally modulated detection signal output from the light receiving element contains only information on line scanning. That is, since most of the information is missing from the digitally modulated detection signal, it is impossible to reproduce the entire information from the detection signal.
In addition, a characteristic part of information may be missing from the digitally modulated detection signal. In particular, when the automobile sways from side to side, the light beam frequently scans the corner cube from various directions.
For example, even if the corner cube is exposed to the beam light, the beam light does not always pass along the mask near the intersection O of the corner cube. The beam of light deviates from the vicinity of the intersection O,
For example, as shown in FIG. 20 (3), the corner cube 1
When passing through the portion δ1 of 11c, the light beam does not pass through the mask. In this case, the corner cube 111c
There is no inhibition of the reflex condition in. Also, FIG.
As shown in (3), the part δ of the corner cube 111c
When passing 2, the mask is passed once. In this case, the detection signal has two pulses, which is the same as the detection signal of FIG. Further, as shown in FIG. 20 (3), when the corner cube 111c passes through the portion δ3, it passes through the mask four times. In this case, the detection signal has five pulses, which is the same as the detection signal of FIG. Therefore, there is a problem that information is often mistakenly recognized.

Further, since the corner cube is scanned by the light beam having a sharp directivity, only the mask of the bar code-like digital code mark composed of the lines which can be distinguished by the line scanning can be arranged. . Also,
In particular, when the car sways to the left or right, the beam light scans the corner cube from various directions, so it is not clear which part of the corner cube the line scans from, and the area of the reflector surface is limited. Has been. Therefore, the number of pieces of information that can be given to the corner cube is limited to a few pieces to a dozen pieces. Therefore, there is a problem that this information transmission system can be used only in a small-scale system.

By the way, there is a demand for transmitting a lot of information to the beam light transmitting / receiving apparatus. In the conventional information transmission system, since information is fixedly attached with a mask,
Only one piece of information can be transmitted from one corner cube. Therefore, in order to transmit a large amount of information to the beam light transmitter / receiver, a plurality of corner cubes must be installed side by side, increasing the installation area of the corner cubes. Moreover, a plurality of corner cubes must be arranged so as to match the line scanning of the light beam. But,
Since it is difficult to apply a beam of light to all corner cubes, and information is often mistakenly recognized, it is practically impossible to increase the amount of information.

The present invention solves the above-mentioned technical problems, can reduce the state where information cannot be transmitted, can reduce misidentification of information, and can be used in a large-scale system. Moreover, it is an object to provide an information transmission system capable of increasing the amount of information.

[0016]

In order to solve the above technical problems, the present invention has the following constitution. The information transmission system according to claim 1 has three light-reflecting mirror surfaces which are arranged in a triangular pyramid shape while maintaining an angle of 90 degrees with each other, and the incident light is incident regardless of the incident angle of the incident light. A corner cube that returns the light at the same angle as the incident angle of light that has been reflected after each light reflecting surface multiple times and is parallel to the incident light; an information transmission device that is arranged in association with the corner cube; and a corner cube. And a beam light transmitting / receiving device disposed at a position separated from each other, and the information transmitting device is linearly or planarly distributed in association with at least one of the respective light reflecting mirror surfaces,
Adhesion between the light-reflecting mirror surface of the corner cube and each shape-changing element is controlled by individually controlling the information signals output to each shape-changing element and a plurality of shape-changing elements that change their shape in response to the information signal.・ Change the form of separation to partially block the reflection of the incident light when the light reflecting mirror surface and each shape change element are in close contact with each other in a dot shape, thereby changing the shape so that the reflected light sequentially contains a plurality of information The beam light transmission / reception device includes an element drive means, and a beam light emitting means for rotating the planar beam light to scan the corner cube and a single or plural light receiving means for receiving the beam light returned from the corner cube. Information recognizing means having an element and sequentially recognizing a plurality of information from the corner cube based on an electric signal output from the light receiving element. According to a second aspect of the present invention, in the information transmission system according to the first aspect, the shape change elements are linearly distributed along at least one of three traverse lines at boundaries between the light reflection surfaces. Is characterized by. According to a third aspect of the invention, there is provided the information transmission system according to the first or second aspect, wherein the plurality of light receiving elements are arranged in a line or a plane.

[0017]

In the information transmission system according to the first aspect, the beam light emitting means scans each corner cube by rotating the planar beam light. Since the beam light has a wide width perpendicular to the scanning direction, the beam light can be easily applied to a small corner cube. Also, because it is wide,
Even if the center of the light beam deviates from the corner cube, the light beam hits the corner cube. This ensures that the beam of light returns from the corner cube. Therefore, the state where information cannot be transmitted can be eliminated. Moreover, since the width of the light beam is wide, the entire surface of the corner cube is scanned. Therefore, the detection signal output from the light receiving element includes all the information, and the characteristic portion of the information is not lost. Therefore, misidentification of information is eliminated. Further, since all the information is included in the detection signal output from the light receiving element, it is not necessary to limit the mask to the digital code mark, and various marks can be used.
This can dramatically increase the number of information items. Therefore, it can be used in a large-scale system. Further, by individually controlling the information signal output to each shape-changing element of the shape-changing element drive means, the mode of contact and separation between the light reflecting mirror surface of the corner cube and each shape-changing element is changed. As a result, the reflection of the light incident when the light reflecting mirror surface and each shape-changing element are in close contact is partially blocked, so that the reflected light sequentially contains a plurality of information. Therefore, the amount of information increases.

According to another aspect of the information transmission system of the present invention, the shape change elements are linearly distributed along at least one of the three traverse lines at the boundaries between the light reflection surfaces. In the case of a single light receiving element, the detection signal of the light receiving element is analog-modulated by the shape change element which is in close contact with the ridge. Therefore, by demodulating the analog-modulated detection signal, the unique information can be extracted more easily. Therefore, the scattered dots are easily blended by the rotational scanning of the planar light beam.

According to another aspect of the information transmission system of the present invention, the plurality of light receiving elements are arranged in a line or a plane. Therefore, the same signal as when each corner cube is visually observed can be extracted from the detection signal of the light receiving element, and complete reproduction of information becomes easy. Therefore, false positives can be eliminated more completely, the number of masks can be increased, and can be used in larger systems.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing an overall configuration of a position detection system for a mobile body using an information transmission system according to an embodiment of the present invention. A corner cube 11 is arranged at a predetermined position beside the road 2 on which the automobile 1 travels. Information transmission device 3 related to the corner cube 11
0 is allocated. The vehicle 1 has a beam light transmitting / receiving device 21.
Is installed. The beam light transmitting / receiving device 21 emits a planar light beam, such as a laser beam LB, which spreads in a fan shape above and below the optical axis center S on a vertical surface while rotating a predetermined angle θ0. By rotating the laser beam LB in this way, it is possible to scan a wide range in a planar shape having a width. The beam light transmitting / receiving device 21 is attached to the automobile 1 so that the optical axis center S of the laser beam LB rotates around the height of the corner cube 11. Each corner cube 11 returns the incident light to the same angle as the incident angle and parallel to the incident light regardless of the incident angle. Therefore, if the laser beam LB emitted from the beam light transmitting / receiving device 21 hits the corner cube 11, the laser beam LB is reflected and the beam light transmitting / receiving device 21 is reflected.
Return to.

First, the beam light transmitting / receiving device 21 will be described in detail. FIG. 2 shows the beam light transmitting / receiving device 21 shown in FIG.
FIG. 3 is a perspective view showing in detail the optical system of FIG. In the figure, the beam light transmitting / receiving device 21 includes a laser light source 21a, a collimator lens 21b, a cylindrical lens 21c, a beam splitter 21d, a mirror 21e, and a motor 21f.
Including and The laser light source 21a is driven by the optical communication device 22 and emits a laser beam. The laser light source 21a, the collimator lens 21b, the cylindrical lens 21c, the beam splitter 21d, the mirror 21e, the motor 21f, and the optical communication device 22 constitute a beam light emitting means. The laser beam emitted from the laser light source 21a is converted into a line beam by the collimator lens 21b, and then the cylindrical lens 21c.
It spreads out like a fan in the two-dimensional direction. The fan-shaped laser beam emitted from the cylindrical lens 21c is given to the mirror 21e via the beam splitter 21d and reflected in the lateral direction of the road 2. The mirror 21e is rotated by the motor 21f. Therefore, the mirror 21
The laser beam LB reflected by f spreads in a fan shape above and below the optical axis center S on the vertical plane, and scans laterally along the roadway 2 over a wide range with a width.

The beam light transmitting / receiving device 21 further includes a lens 2
3a and a single light receiving element 23b. Light receiving element 23
Information recognition means is configured by b and the optical communication device 22. The laser beam LB is one of the corner cubes 11a ...
When the light is emitted to the corner 11c, the reflected light from the corner cube 11 returns to the beam light transmitting / receiving device 21, is reflected by the mirror 21e, and is then branched by the beam splitter 21d toward the lens 23a. The lens 23a focuses the reflected light from the corner cube 11 on the light receiving surface of the light receiving element 23b. The light-receiving element 23b converts the detected reflected light from the corner cube 11 into an electric signal,
It is output to the optical communication device 22.

FIG. 3 is a block circuit diagram of the optical communication device 22 shown in FIG. System bus 2 of optical communication device 22
2a includes a CPU 22b, a ROM 22c, and a RAM 22.
d, the A / D converter 22e, the interface 22f, etc. are connected. Various information of the corner cube 11, programs for operating this system, and the like are stored in advance in the ROM 22c. The CPU 22b is
The programs stored in the ROM 22c are executed to perform on / off control of the laser light source 21a and rotation control of the motor 21f. The detection signal output from the light receiving element 23b is analog-digital converted in the A / D converter 22e. The CPU 22b temporarily stores the digitally converted detection signal in the buffer area of the RAM 22d. Next, the CPU 22b executes the demodulation process and stores the detection signal after the demodulation process in the data area of the RAM 22d.
Next, the CPU 22b determines whether the detection signal stored in this data area matches the information stored in the ROM 22c. Then, the CPU 22b displays the determination result and the like on the monitor via the interface 22f.

Next, the corner cube 11 will be described in detail. FIG. 4 is a side view of the corner cube 11, and FIG. 5 is a front view of the corner cube 11. The corner cube 11 has three light reflecting mirror surfaces 12, a light reflecting mirror surface 13, and a light reflecting mirror surface 14. These light reflecting mirror surfaces 12, 13 and 14 are arranged in a triangular pyramid shape while maintaining an angle of 90 degrees with each other. Here, the corner cube 11
Consider the light A that is incident on A at an incident angle θ1. The incident light A is reflected by, for example, the light reflecting mirror surface 14, and then is reflected by, for example, the light reflecting mirror surface 13, and the light reflecting mirror surfaces 12, 13,
Reflected light A ′ from a position symmetrical with respect to the mutual intersection O of 14
Is emitted as. At this time, the reflection angle of the reflected light A ′ is the same as the incident angle θ1 of the incident light A, and the reflected light A ′ and the incident light A are parallel. Even when the incident light B is incident, the reflection angle of the reflected light B ′ is the incident angle θ of the incident light B.
The reflected light B ′ and the incident light B are parallel to each other at the same angle θ2 as 2. This relationship is established regardless of the incident angle of incident light. Therefore, when the laser beam LB emitted from the beam light transmitting / receiving device 21 is incident on the corner cube 11, the laser beam LB is reflected and returns to the beam light transmitting / receiving device 21.

Next, the information transmission device 30 will be described in detail. FIG. 6 shows an information transmission device 30 of an embodiment arranged in association with the light reflecting mirror surface 12 of the corner cube 11.
It is a figure which shows the structure of. The information transmitting device 30 includes an optical modulator 4 and an electrostrictive element driver 7 as a shape changing element drive unit. In this embodiment, the light modulator 4 is attached to the light reflecting mirror surface 12 of the corner cube 11. The optical modulator 4 is driven by the electrostrictive element driver 7.

FIG. 7 is a view of a part of the optical modulator 4 of FIG. 6 viewed from the direction of the light reflecting mirror surface 12, and FIGS. 8 and 9 are enlarged views of a part indicated by a dotted line A in FIG. For example, the optical modulator 4 is configured by disposing a plurality of electrostrictive elements 41 as shape changing elements in a matrix on a common substrate 40. An insulating spacer 42 is provided in the gap between the electrostrictive elements 41. Each insulating spacer 42 is made of a flexible material such as resin. These insulating spacers 4
By 2, the electrostrictive elements 41 are insulated from each other and the electrostrictive elements 41 are individually displaceably connected.

Each electrostrictive element 41 is an element whose shape changes according to an applied electric field, and is, for example, a piezoelectric material such as tourmaline, quartz, Rochelle salt, barium titanate, calcium phosphate, lead zirconate or lead titanate. It consists of elements.

Although not shown, wiring is individually provided on the substrate 40 for each electrostrictive element 41. The electrostrictive element driver 7 outputs an information signal to each electrostrictive element 41 through these wirings, and individually drives each electrostrictive element 41.

Next, the operation of the embodiment shown in FIGS. 6 to 9 will be described. As shown in FIG. 8, each electrostrictive element 41 is arranged at a predetermined distance from the light reflecting mirror surface 12 of the corner cube 11. Therefore, in this state, all the light that has entered the light reflecting mirror surface 12 is reflected as shown by the alternate long and short dash line, and again exits from the entrance surface 15 of the corner cube 11 to the outside.

On the other hand, when an electric field is applied to any of the electrostrictive elements 41 by the electrostrictive element driver 7, the shape of the electrostrictive element 41 changes, and the light reflecting mirror surface 12 of the corner cube 11 becomes a dot shape. In close contact. For example, in FIG. 9, the second electrostrictive element 41 from the left and the third electrostrictive element 4 from the right.
1 and 1 are in close contact with the light reflecting mirror surface 12 in a dot shape. As a result, by bringing the electrostrictive element 41 into close contact with the light reflecting mirror surface 12, it becomes equivalent to disposing a dot-shaped mask on the light reflecting mirror surface 12. Therefore, the electrostrictive element driver 7
By individually controlling the change in the shape of each electrostrictive element 41, an arbitrary number of electrostrictive elements 41 can be brought into close contact with each other in arbitrary positions on the light reflecting mirror surface 12 in a dot shape.

Now, the relationship between the light reflecting mirror surface 12 and the electrostrictive element 41 when the electrostrictive element 41 of the optical modulator 4 is individually controlled by the electrostrictive element driver 7 will be described in detail. Figure 10
FIG. 3 is a front view of the corner cube 11 as viewed from the front.
When the information signals for applying electric fields to the predetermined four electrostrictive elements 41 are output from the electrostrictive element driver 7 to the optical modulator 4, the four electrostrictive elements 41 come into close contact with the light reflecting mirror surface 12. As a result, on the light reflecting mirror surface 12 of the corner cube 11, a mask pattern 31 made up of four dots d scattered to represent information is arranged at a predetermined position (see FIG. 10 (1)). The above-mentioned reflection condition is maintained in the portion where the dot d is not attached. However, when the incident light is directed to the dot d, the incident light is not reflected because it is absorbed by the dot d and the reflection condition is hindered. Here, the light reflecting mirror surface 13
There is a case where the light reflected by is reflected by the light reflecting mirror surface 14 or directly passes through the dot d on the light reflecting mirror surface 12. Also in this case, the reflection condition is obstructed, so that no reflection occurs. That is, the mask pattern 31 is formed on the light reflecting mirror surface 12.
By disposing, the virtual mask pattern 31 is formed on a virtual surface obtained by extending the light reflecting mirror surface 12 with the intersection O as the center.
This is equivalent to arranging a, 31b, and 31c. Therefore, 16 dots d are scattered around the intersection O.

For a predetermined time (for example, the beam light transmitting / receiving device 2
(1 is longer than one scan time), the electrostrictive element driver 7 causes the optical modulator 4 to send the predetermined seven electrostrictive elements 4 to each other.
When an information signal for applying an electric field to 1 is output, the seven electrostrictive elements 41 come into close contact with the light reflecting mirror surface 12.
As a result, the light reflecting mirror surface 12 of the corner cube 11
In order to express information, a mask pattern 32 composed of seven dots d scattered at a higher density than that in the case of FIG. 10A is arranged at a predetermined position (see FIG. 10B). In this case, three virtual mask patterns 3
This is equivalent to arranging 2a, 32b and 32c as well. Therefore, for this reason, 28 dots d are scattered about the intersection points O.

Next, when the information signals for applying the electric fields to the predetermined three electrostrictive elements 41 are output from the electrostrictive element driver 7 to the optical modulator 4 after a predetermined time has elapsed, these three electrostrictive elements are output. 41 is in close contact with the light reflecting mirror surface 12. As a result, on the light reflecting mirror surface 12 of the corner cube 11,
In order to represent information, a mask pattern 33 composed of three dots d scattered at a lower density than in the case of FIGS. 10A and 10B.
Are arranged at predetermined positions (see FIG. 10 (3)). In this case, three virtual mask patterns 3
This is equivalent to arranging 3a, 33b, 33c as well. Therefore, nine dots d are scattered about the intersection points O for this reason.

In this way, the information signal is output from the electrostrictive element driver 7 to the optical modulator 4, and each electrostrictive element 4 of the optical modulator 4 is output.
By controlling 1 individually, the reflection condition is obstructed and light is not reflected. As a result, the reflected light can include arbitrary information. Also, by changing the information signal output from the electrostrictive element driver 7, the information contained in the reflected light can be changed sequentially.

Here, the operation of the position detecting system for the moving body will be described with reference to FIGS. Note that FIG.
The waveform diagram of the detection signal of the light receiving element 23b is shown in FIG. When this system is operated, the CPU 22b of the optical communication device 22
Turns on the laser light source 21a and controls the rotation of the motor 21f. As a result, the planar laser beam LB is emitted from the beam light transmitting / receiving device 21 to the side of the road 2 while being rotated. When the automobile 1 approaches the corner cube 11, the laser beam LB emitted from the beam light transmitting / receiving device 21 has a wide width perpendicular to the turning direction, so that the corner cube 11 is always hit with the laser beam LB.
Further, since the width is wide, the laser beam LB always hits the corner cube 11 even when the automobile 1 sways left and right and the optical axis center S of the laser beam LB deviates from the corner cube 11. As a result, the laser beam LB always returns from the corner cube 11 to the beam light transmitting / receiving device 21. Therefore, the state where information cannot be transmitted can be eliminated.

It is assumed that the laser beam LB emitted from the beam light transmitting / receiving device 21 hits the corner cube 11, and the optical axis center S of this laser beam LB scans, for example, the part α of the corner cube 11 (FIG. 10).
(See (1)). In this case, the laser beam LB exists perpendicular to each of the optical axis centers S. Therefore, the laser beam LB sequentially scans the entire surface of the corner cube 11 in a slit shape perpendicular to the optical axis center S. On the other hand, the laser beam LB is reflected in the portion other than the dot d, but is reflected in the portion of the dot d. Therefore, the light receiving element 23b sequentially views the corner cube 11 while integrating the slit-shaped reflected light perpendicular to the optical axis center S. Therefore, in the state where there is no dot d in the corner cube 11,
Since the laser beam LB is totally reflected, the light receiving element 23
As shown in FIG. 11 (1), b outputs a generally semi-cylindrical detection signal (indicated by reference numeral q). However, the dot d is attached to the corner cube 11. Therefore, the reflection of the laser beam LB is obstructed by the amount of the dot d. Light receiving element 2 due to the decrease in the reflected light of this dot d
The drop of the detection signal of 3b is indicated by reference numeral r1. Therefore, the light receiving element 23b sequentially outputs the detection signal V1 at the level of (q-r1) per unit time as shown in FIG. 11 (1). Therefore, since the detection signal V1 output from the light receiving element 23b is analog-modulated by the mask patterns 31, 31a, 31b, 31c of the dots d, the detection signal V1 includes all the information from the corner cube 11. ing.

After a predetermined time has elapsed, when the optical axis center S of the laser beam LB emitted from the beam light transmitter / receiver 21 linearly scans the portion β of the corner cube 11, for example, the reflection of the laser beam LB is reflected by the corner cube 11. Is blocked by the dot d. The drop in the detection signal of the light receiving element 23b due to the decrease in the reflected light of the dot d is referred to by the reference symbol r.
2 (see FIG. 11 (2)). Therefore, the light receiving element 23b sequentially outputs the detection signal V2 at the level of (q-r2) per unit time as shown in FIG. 11 (2). Therefore, the detection signal V2 output from the light receiving element 23b is generated by the mask patterns 32, 32 of the dots d.
Since the signals are analog-modulated by a, 32b, and 32c, the detection signal V2 includes all the information from the corner cube 11.

After the lapse of a predetermined time, when the optical axis center S of the laser beam LB emitted from the beam light transmitter / receiver 21 linearly scans, for example, the part γ of the corner cube 11, the laser beam LB is reflected by the corner cube 11. Is blocked by the dot d. The drop in the detection signal of the light receiving element 23b due to the decrease in the reflected light of the dot d is referred to by the reference symbol r.
3 (see FIG. 11 (3)). Therefore, the light receiving element 23b sequentially outputs the detection signal V3 having the level of (q-r3) per unit time as shown in FIG. 11 (3). Therefore, the detection signal V3 output from the light receiving element 23b is generated by the mask patterns 33, 33 formed by the dots d.
Since it is analog-modulated by a, 33b, and 33c, the detection signal V3 includes all the information from the corner cube 11.

Detection signal V output from the light receiving element 23b
1, V2 and V3 are A / D converters 22 of the optical communication device 22.
Analog-to-digital conversion is performed at e. CPU 22b
Temporarily stores the digitally converted detection signal in the buffer area of the RAM 22d. Next, the CPU 22b executes the demodulation process and outputs the detection signal after the demodulation process to the RAM 2
Store in the 2d data area. Then, the CPU 22b
Indicates the detection signal stored in this data area and the ROM 2
It is determined whether or not the information stored in 2c matches. Since the width of the laser beam LB is wide, the entire surface of the corner cube 11 is scanned, so that the light receiving element 2
The detection signals V1, V2, V3 output from 3a include all of the information, and a characteristic portion of the information (for example, the number of dots d, the dots d are dense in the corner cube 11a,
The dot d is dense in the corner cube 11b, and the dot d is rough in the corner cube 11). Therefore, there is no misidentification of each information sequentially sent from the corner cube 11. Also, a plurality of scattered dots d
Is easily adapted to the rotational scanning of the planar laser beam LB.

After the determination of each information, the CPU 22b
The judgment result is displayed on the monitor via the interface 22f. Further, the CPU 22b provides the determination result and the like to the utilization device (for example, the position calculation device, the automatic steering device, etc.) via the interface 22f. The utilization device stores in advance absolute position information of each corner cube 11, for example. Then, the absolute position information is read correspondingly based on the judgment result given from the optical communication device 22, the current position of the automobile 1 is calculated, and the calculation result is displayed on the monitor. At this time, the rotation angles (θa, θ) of the laser beam LB when the reflected light from the corner cube 11 is received.
If b, θc) is used as a parameter for position calculation, information regarding the position can be obtained.

The entire surface of the corner cube 11 is scanned and the detection signal V output from the light receiving element 23b.
1, V2 and V3 include all the information. Therefore, even when the mask patterns 131, 132, 133 shown as analog marks in FIG. 20 are scanned, the detection signals V1, V output from the light receiving element 23b are detected.
2, V3 includes all the information of the mask patterns 131, 132, 133, and can be easily discriminated. Therefore, it is not necessary to limit the mask pattern to the digital code mark, and various marks having different numbers of dots, arrangement positions of dots, and the like can be used. This can dramatically increase the number of information items. Therefore, it can be used in a large-scale system. Moreover, since the information can be changed sequentially, the amount of information can be dramatically increased.

FIG. 12 is a diagram showing the structure of another embodiment of an information transmitting device 30 arranged in association with the corner cube 11. It should be noted in this embodiment that the light modulator 4 is the light reflecting mirror surface 12 and the light reflecting mirror surface 1 of the corner cube 11.
It is arranged in relation to the ridgeline L1 of the boundary with the No. 4.
In this case, when an electric field is applied to any of the electrostrictive elements 41 by the electrostrictive element driver 7, the electrostrictive element 41 is
It adheres to the ridge line L1 in a dot shape.

Here, the relationship between the light reflecting mirror surface 12 and the electrostrictive element 41 when the electrostrictive element 41 of the optical modulator 4 is individually controlled by the electrostrictive element driver 7 will be described in detail. FIG.
FIG. 3 is a front view of the corner cube 11 as viewed from the front.
When the electrostrictive element driver 7 outputs information signals for applying an electric field to the predetermined three electrostrictive elements 41 to the optical modulator 4, the three electrostrictive elements 41 are in close contact with the ridge line L1.
Therefore, the mask pattern 34 including the three dots d linearly arranged along the ridge line L1 is arranged at a predetermined position. In this case, since one virtual mask pattern is in close contact with the mask pattern 34, it is hidden by the mask pattern 34. The other two virtual mask patterns are in close contact with each other. For this reason,
This is equivalent to disposing one virtual mask pattern 34a. The dots d of the mask pattern 34a are formed on the extension lines of the ridge line L1. Therefore, the six dots d are arranged in a straight line.

Here, it is assumed that the optical axis center S of the laser beam LB emitted from the beam light transmitting / receiving device 21 linearly scans, for example, the part ε of the corner cube 11. Note that FIG. 14 shows a waveform diagram of the detection signal of the light receiving element 23b. The reflection of the laser beam LB is blocked by the dot d of the corner cube 11. The drop in the detection signal of the light receiving element 23b due to the decrease in the reflected light of the dot d is indicated by reference numeral r4. Therefore, the light receiving element 23b has
As shown in FIG. 4, the detection signal V4 having a level of (q-r4) per unit time is sequentially output. Therefore, since the detection signal V4 output from the light receiving element 23b is analog-modulated by the mask patterns 34 and 34a formed by the dots d, the detection signal V4 includes all the corner cube 11c information. Therefore, this information can be easily recognized. Especially in this case, the twill line L
Since the dots d are arranged in a straight line along the line 1, the dots are easily adapted to the rotational scanning of the planar laser beam LB.

FIG. 15 shows the beam light transmitting / receiving device 2 shown in FIG.
It is a perspective view which shows the other optical system of 1 in detail. What should be noted in this embodiment is that the line sensor 43b is used instead of the single light receiving element 23a. The line sensor 43b includes a plurality of light receiving elements arranged in a line. The line sensor 43b looks at the entire surface of the corner cube 11 for each pixel. For this reason,
From the detection signal V of the line sensor 43b, the same signal as when the corner cube 11 is visually observed can be taken out, and the complete reproduction of information is facilitated by the light receiving element 23a. Therefore, false positives can be eliminated more completely,
The number of mask patterns can be increased and can be used in a larger system. The detection signal output from the line sensor 43b is analog-digital converted in the A / D converter 22e. CP
U22b stores the digitally converted detection signal in the RAM22.
It is temporarily stored in the buffer area of d. Then the CPU 22
b executes binarization processing, and stores the detection signal after binarization processing in the data area of the RAM 22d. Then C
The PU 22b determines whether the detection signal stored in this data area matches the information stored in the ROM 22c. Since the binarization process is easier than the demodulation process, the determination process is easier. In this case, for example, even if the number of dots d is the same, it can be recognized that the information is different if the positions of the dots are different.

FIG. 16 shows a beam light transmitting / receiving device 2 shown in FIG.
It is a perspective view which shows the other optical system of 1 in detail. In this embodiment, it should be noted that the two-dimensional sensor 53b is used instead of the single light receiving element 23a and the line sensor 43b. The two-dimensional sensor 53b is composed of a plurality of light receiving elements arranged in a plane. This two-dimensional sensor 53b is
Similar to the line sensor 43b, the entire surface of the corner cube 11 is viewed pixel by pixel. Therefore, from the detection signal V of the two-dimensional sensor 53b, the same signal as when the corner cube 11 is visually observed can be taken out, and the complete reproduction of information from the light receiving element 23a becomes easy. Therefore, misidentification can be completely eliminated, the number of mask patterns can be increased, and the system can be used in a larger system. Two-dimensional sensor 5
The detection signal output from 3b is analog-digital converted in the A / D converter 22e. The CPU 22b is
The digitally converted detection signal is temporarily stored in the buffer area of the RAM 22d. Next, the CPU 22b executes the binarization process and outputs the detection signal after the binarization process to the RAM2.
Store in the 2d data area. Then, the CPU 22b
Indicates the detection signal stored in this data area and the ROM 2
It is determined whether or not the information stored in 2c matches. Since the binarization process is easier than the demodulation process, the determination process is easier. Even in this case, for example, even if the number of dots d is the same, it can be recognized that the information is different if the positions of the dots are different.

FIG. 17 is a diagram showing the configuration of a control system for a moving body in which the information transmission system according to the embodiment of the present invention is used. The same reference numerals are used for the portions corresponding to those of the embodiment of FIG. Attach. In the figure, a plurality of columns 61 are provided upright at the four corners of the intersection, and a plurality of beam light transmitting / receiving devices 21 are fixedly supported by these columns 61. Each beam light transmitting / receiving device 21 scans the vehicle 1 entering the intersection by rotating and scanning the laser beam LB toward each traveling lane of the road 2. On the other hand, each vehicle 1 has a corner cube 11 and an information transmitting device 30.
Is provided to modulate the laser beam LB emitted from the beam light transmitting / receiving device 21 and to transmit the beam light transmitting / receiving device 21.
Reflect toward.

FIG. 18 is a block diagram showing the overall structure of the control system for a moving body shown in FIG. 17, and the portions corresponding to those in FIG. 3 are designated by the same reference numerals. In the figure, the control device 25 is composed of, for example, a microcomputer, and is connected to the optical communication device 22 of the beam light transmitting / receiving device 21 via an interface 22f. Further, the control device 25 is connected to the host computer 51 in the control center 5 via a wireless or wired communication path 6. The host computer 51 is also connected to another beam light transmission / reception device 21 (not shown), and the plurality of beam light transmission / reception devices 2 are connected.
Centrally manage the traffic information sent from one. In the control center 5, the host computer 51 is connected to the center display device 52. This center display device 52
Displays traffic conditions on the road (for example, traffic jams, accidents, etc.) based on display data generated by the host computer 51.

Preferably, a traffic signal control device 71 and a traffic information display device 72 are connected to the control device 25. The traffic signal control device 71 controls the lighting state of the traffic signal device provided on the road based on the control data given from the control device 25. Traffic information display device 72
Is based on the display data given from the controller 25,
Display various traffic conditions.

From the host computer 51 to the controller 25
Is given various control data for controlling the vehicle. The control device 25 creates an activation signal based on the control data provided from the host computer 51,
It is output to the optical communication device 22. The optical communication device 22 activates the laser light source 21a according to the applied start signal.
Thereby, the beam light transmitting / receiving device 21 emits the laser beam LB to the traveling lane of the road 2 while rotating the laser beam LB. Then, the optical communication device 22 sequentially determines a plurality of pieces of information of the corner cube 11 of each automobile 1. This judgment result is sent to the host computer 51 in the control center 5 via the control device 25 and the communication path 6.

The host computer 51 in the control center 5 creates display data indicating the traffic condition of each road based on the information sent from the plurality of beam light transmitting / receiving devices 21. The display data created by the host computer 51 is given to the center display device 52. Therefore, the traffic condition of each road is displayed on the center display device 52. Furthermore, the host computer 5 of the control center 5
1 creates control data of traffic signals and display data of traffic conditions based on the information given from each beam transmitting / receiving device 21, and sends it to the control device 25 via the communication path 6.

The controller 25 is a host computer 51.
The traffic signal control device 71 controls the lighting state of the traffic signal based on the control data of the traffic signal given by For example, when a traffic jam occurs at a certain location on the road, the traffic congestion can be eliminated promptly by controlling the lighting status of multiple traffic signals provided at that location so that the vehicle can flow well. You can Further, the control device 25 causes the traffic information display device 72 to display the traffic condition of the surrounding road based on the traffic condition display data provided from the host computer 51. The traffic information display device 72 is provided along each road, and guides and displays the traffic conditions of the surrounding roads to the driver of the automobile 1. This allows the driver to drive smoothly toward the destination. For example, when a traffic jam occurs on the way to the destination, the driver can bypass the road where the traffic jam occurs and shorten the time to reach the destination.

In the above embodiment, the information transmission system is used as an example of a mobile body for a position inspection system and a traffic control system applied to a vehicle traveling on a road, but other mobile bodies (unmanned It may be used for a position inspection system, a traffic control system for a carrier vehicle, a mobile robot, an aircraft, a ship, a bicycle, a motorcycle, etc., such as occupants, pedestrians, etc., such as an air traffic control system, a navigation system, etc. It may be used in another system. Further, in the above-mentioned embodiment, the electrostrictive elements of the optical modulator are arranged in the form of a matrix, but they may be arranged in a plane of another shape, or arranged in a line. You may make it implement. Although the electrostrictive element is provided in association with the light reflecting mirror surface 12, the electrostrictive element may be provided in association with the other light reflecting mirror surfaces 13 and 14. Further, although the electrostrictive element is provided along the ridgeline L1, the electrostrictive element may be provided in association with the other ridgelines L2 and L3. Further, the electrostrictive element is used as the shape changing element, but a piezoelectric element such as a piezo element may be used. Further, the following information is sent from the corner cube after a time longer than one scanning time of the beam light transmitting / receiving device, but the next information may be sent after the same time as one scanning time passes. Alternatively, a light receiving device may be provided on the corner cube side, and the following information may be sent by synchronizing with the light beam by this light receiving device.

[0054]

In the information transmission system according to the first aspect of the invention, since the beam light emitting means rotates the planar beam light to scan each corner cube, the beam light can be easily applied to a small corner cube. Since the beam light always returns from the corner cube to the beam light transmitting / receiving device, it is possible to eliminate a state where information cannot be transmitted. Further, since the width of the light beam is wide, the entire surface of the corner cube is scanned, and all the information is included in the detection signal output from the light receiving element, so that misidentification of information is eliminated. Further, since all the information is included in the detection signal output from the light receiving element, various marks can be used, and the number of information can be dramatically increased, so that it can be used in a large-scale system. . Moreover, since the reflected light sequentially includes a plurality of information, the amount of information is dramatically increased.

In the information transmission system of claim 2,
Since the shape change elements are linearly arranged along at least one of the three traverse lines at the boundaries between the respective light reflecting surfaces, when the light receiving element is single, the detection signal of the light receiving element is along this ridgeline. It is analog-modulated by the shape-changing element that is in close contact, and is easily adapted to the rotational scanning of the planar light beam. By demodulating this detection signal, information can be extracted more easily.

In the information transmission system according to the third aspect, since the plurality of light receiving elements are arranged in a line or a plane,
From the detection signal of the light receiving element, a signal similar to that obtained by visually observing each corner cube can be extracted, and complete reproduction of information becomes easy.

[Brief description of drawings]

FIG. 1 is a perspective view showing an overall configuration of a position detection system for a mobile body using an information transmission system according to an embodiment of the present invention.

2 is a perspective view showing in detail an optical system of the beam light transmitting / receiving device 21 shown in FIG.

3 is a block circuit diagram of the optical communication device 22 shown in FIG.

FIG. 4 is a side view of the corner cube 11.

5 is a front view of the corner cube 11. FIG.

FIG. 6 is a diagram showing a configuration of an information transmission device 30 of an embodiment arranged in association with a light reflecting mirror surface 12 of a corner cube 11.

7 is a view of a part of the optical modulator 4 of FIG. 6 viewed from the direction of the light reflecting mirror surface 12;

FIG. 8 is an enlarged view of a portion indicated by a dotted line A in FIG.

9 is an enlarged view of a portion indicated by a dotted line A in FIG.

FIG. 10 is a front view of the corner cube 11 with a mask pattern as seen from the front.

FIG. 11 is a waveform diagram of a detection signal of the light receiving element 23b.

FIG. 12 is a diagram showing a configuration of an information transmission device 30 of another embodiment arranged in association with the corner cube 11.

FIG. 13 is a front view of the corner cube 11 as seen from the front.

FIG. 14 is a waveform diagram of a detection signal of the light receiving element 23b.

15 is a perspective view showing in detail another optical system of the beam light transmitting / receiving device 21 shown in FIG.

16 is a perspective view showing in detail another optical system of the beam light transmitting / receiving device 21 shown in FIG.

FIG. 17 is a diagram showing a configuration of a control control system for a mobile body using the information transmission system according to the embodiment of the present invention.

FIG. 18 is a block diagram showing an overall configuration of the mobile traffic control system shown in FIG. 17.

FIG. 19 is a diagram showing an overall configuration of a position detection system for a moving body using a conventional information transmission system.

FIG. 20 is a front view showing a corner cube 111 provided with a mask.

FIG. 21 is a diagram showing a detection signal of the light receiving element in the conventional information transmission system.

[Explanation of symbols]

 4 ... Optical modulator 7 ... Electrostrictive element driver 11, 11a, 11b, 11c ... Corner cube 12, 13, 14 ... Light reflecting mirror surface 21 ... Beam light transmitting / receiving device 21a ... Laser light source 21b ... Collimator lens 21c ... Cylindrical lens 21d ... Beam splitter 21e ... Mirror 21f ... Motor 22 ... Optical communication device 23b ... Light receiving element 30 ... Information transmitting device 41 ... Electrostrictive element 43b ... Line sensor 53b ... Two-dimensional sensor d ... Dots L1, L2, L3 ... Ridge line

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nobuo Komatsu 4-22-13 Minamiyata, Higashisumiyoshi-ku, Osaka

Claims (3)

[Claims] 1. A light-reflecting mirror surface, which has three light-reflecting mirror surfaces that are arranged in a triangular pyramid shape while keeping an angle of 90 degrees with each other, and makes incident light incident on each of the light rays. A corner cube that returns to the same angle as the incident angle of the light that is incident after being reflected a plurality of times on the reflecting surface and is parallel to the incident light, an information transmission device that is arranged in relation to the corner cube, and the corner cube. A light beam transmitting / receiving device arranged at a distance from each other, wherein the information transmitting device is linearly or planarly distributed in association with at least one of the light reflecting mirror surfaces and responds to an information signal. And a plurality of shape change elements for changing the shape thereof, by individually controlling the information signal output to each of the shape change elements, close contact between the light reflecting mirror surface of the corner cube and each of the shape change elements Remote The shape change element that partially blocks reflection of incident light when the light reflecting mirror surface and each shape change element are in close contact with each other in a dot shape, thereby sequentially including a plurality of information in the reflected light. The beam light transmitting / receiving device includes a drive unit, a beam light emitting unit that rotates the planar beam light to scan the corner cube, and a single or plural beam light receiving unit that receives the beam light returned from the corner cube. And an information recognizing unit that sequentially recognizes a plurality of pieces of information from the corner cube based on an electric signal output from the light receiving element. 2. The shape-changing elements are linearly distributed along at least one of three traverse lines at boundaries between the light-reflecting surfaces. Information transmission system. 3. The information transmission system according to claim 1, wherein the plurality of light receiving elements are arranged in a line shape or a plane shape.